Perk 1: Scavenger Perk 2: Assasin Perk 3: Dead Silence
Killstreak Package: Support [UAV, Advanced UAV(or stealth bomber) and Osprey support] Deathstreak: Final Stand
I use this set-up because i like being stealthy and sneaking up behind the enemy whilst my team goes head on, i find this class works well on most levels and really helps you seeek out and destroy your targets, i use scavenger on most my classes as i find its the best top line one to use for the way i play, i'm not used to going around running out of ammo and having to pick up other guns, i like using my gun and keeping it full of ammo, plus scavenger also gets you an extra attachment (Extended mags) which if you combine that with extended mags like i have, you get almost as many bullets per clip as an LMG!
I don't really use secondary weapons but occasionally i like to switch and use the akimbo TMPs, theres no really decent selection of secondaries unlike in other COD games, but i don't like using guns that everyone else uses constantly (yeah i know i contradict myself using the MP7 but i'm talking about guns like FMG's, PP90M1, ACR and SCAR-L).
The Assasin perk i use because i don't really find the other perks help me as much as being silent and undectectable does, now for me my tactic is all about getting behind enemy lines and not being noticed, i also end up going against people who have whored this game forever and have very fast reflexes or mods that help them aim quicker so i need to be unseen as a way of beating them, with assasin i use it mainly so i don't show up on their UAV or thermal, but assasin also helps if your playing dead because Pro removes red target on enemy crosshair and doesn't show your name so enemies take that few extra split seconds to make the decision to shoot you or not. With this i find dropping on the floor and tap triangle repeatedly makes you less likely to be spotted as still alive as you appear to be a dead body on the floor and only certain people will actually tell the difference between a "REAL" dead body and your "Fake" dead body. Assasin gets you out of tight situations too as it also helps you avoid campers with heartbeat sensors.
Now we move to dead silence, if i were to use any other third perk other than this, it would be steady aim but i prefer the fact i can't hear my own footsteps, this means i can listen out for enemy footsteps and take action to avoid them or kill them, the added benefit to dead silence is that in pro it stop your from taking falling damage which i find very useful when running to avoid being shot, i can jump off high places that would normally kill you and escape which means if the enemy isn't using dead silence they will either have to stop and try and shoot me from the high point, or try following me and die in the process. This perk works really well with a silenced weapon because it completely makes you stealthy.
Now alot of people in Mw3 critisize players for using the support packages and to an extent i can see their points, Support packages tend to be used by people who cannot play COD games and need a helping hand to get decent killstreaks, but my reasoining for using support packages isn't because they don't reset if you die, but because i'm a big fan of stealth bomber and advanced UAV i use this package, i like the UAV streaks because you can detect enemies on your HUD and whilst your running around undetected its easy to get kills, now my last streak is the 18 kills one which drops care packages and protects them, i only tend to try and get these if i get anything good, but i tend to leave them for my team.
The final stage of my class is the deathstreak, while i don't normally ever use it because i don't die that often i use it mainly to get an extra kill is final stand, this deathstreak is useful if your one on one with someone but is kind of a pussy deathstreak, the only reason i use it is because the others are either crap or even more pussy, but its useful if you manage to survive and get back up, meaning you can continue your killing without taking a death.
Perk 1: Scavenger
Perk 2: Assasin
Perk 3: Dead Silence
Killstreak Package: Specialist [Sleight of hand, Blast shield and Steady aim]
Deathstreak: Final Stand
I started using this class recently and loved it ever since, basically i'm quite into getting all the kills for myself rather than using the killstreaks in assult and support so i use this class in a similar way to you Neo, i like to run around un-noticed on the flanks and get behind the enemy and stay as close to them as possible, this class is brilliant for this as the P90 has an awesome mag size and deals some nice damage, i sometimes swap Kick for attachments and go with extended mags for longer periods of bullet rain on the enemy. the first perks are set up to be stealthy and the specialist perks are set up to be more kill assisted and protection (blast shield for stun protection mainly) since specialist perks only take 2 kills to start off and 6 kills to get all three its fast and easy to attain all three and then go for the 8 kill streak which unlocks ALL perks, after 8 you can run around like a killing machine and it also helps you gain PRO for perks you don't use often.
I could recomend starting out with hardline instead of assasin to get your ALL perks quicker, but it means losing out on assasin for a few kills which can sometimes mean you get 3 kills then die and have to start over. so its more of personal choice.
Killstreak: Speciality [Hardline, Sleight of hand, Blind Eye]
I love this set-up as the Dagonuv sniper is very under-rated, sure it takes 2 hits anywhere except the head but you can fire it fast and with Kick the recoil is very easy to handle. The downside to this set up is that its not very good close range so i tried to combat that with the P99 with tactical knife to stab enemies, the difficulty with close range is that (with all Snipers) the scope zooms you in and is slower to ADS than other guns (even though Dragonuv has one of the fastest scopes of the snipers). but blindfiring is almost ineffective with a dragonuv.
I tend to use Speciality killstreaks too as i prefer this class when i get blindeye and sleight of hand, however i chose hardline first to get the other faster (and i know your all thinking i should of chosen it as a second perk and asassin as first special but hear me out). The reason for this is due to the fact most people have UAV and Advanced UAV out most of the time so using harline first normally means i lose a couple of deaths before i can get my assasin perk so i swapped them round to combat this and i find it works far better.
Killstreak: Assult [ Predator | Attack Helicopter | Pavelow ]
Deathstreak: Final Stand
Now this class is ridiculously good on games like domination on Arkaden, Dome and Resistance and works well in most maps, this gun is incredibly stable with a silencer and kick so the reciol is reduced dramatically, the high rate of fire more than makes up for the damage it has (Bare in mind It has the least damage of all LMG's (i think) but has highest fire rate).
This LMG rips through kills like a psycho on a mission and pick your spots carefully and its almost impossible for people to take you out, the Scavenger perk allows you additional clip size (meaning you hardly need to reload) and with an extra 200 bullets with scav pro you won't need to worry about wasting ammo an easy choice over the other perks in that line. Stalker ensures you can move fast whilst aiming down your site which gives you a massive advantage against people trying to pick you off as you can strafe left and right to avoid gunfire.
Assasin uis there just so you don't show up on radar and the silencer means that people won't be rushing in to kill you when you've fired your gun as you won't show up, meaning if you hold down a small area (EG a flag) you'll find that people will rush the flag and not you, leaving you to hammer away at anyone who is dumb enough to walk into your sights.
Because i don't die a lot with this class i slapped on Pred for the first killstreak to ensure i have a chance at quickly gaining an additional kill or more to ensure i get my attack heli, i then let that do some far away killing whilst i still guard a flag and pound away at the enemies (the heli is good since you don't need to control it) the only downside to the heli is that mine seems to only get a kill or two before being shot down (yet my team mates helis can be left untouched for the duration). once i've got enough kills it'll be time to bring in the big guns. now the Pavelow is a pretty overlooked killstreak and many prefer to favor the AC130, now from experience i'm not that brilliant with the AC130 so for me i'd rather be on the ground fighting and letting my airsupport kill from above meaning 1. i'm not vunerable on the floor while i control anything and 2. technically double the fire power and the pavelow has loads better bullet penetration. Once i was in a game where my pavelow got me around 13-16 kills before departing leaving me on the ground picking off any stragglers who had blind eye on.