Gun with 1 Attachment Launcher - Hardline - Scavenger - Engineer Black Hat EMP Grenade 2X
Killstreaks: - UAV - Care Package - Counter UAV
Tactics: The goal is to get the UAV out by getting to 360 points while playing a defensive role and avoid combat as much as possible until your first UAV. - You can get up to 200 points by chucking EMPs and getting points from assists. - Up to 150 points can be earned by shooting down UAVs. Even more points for shooting down more powerful aircraft. - If you use the PDW, you can provide Suppressive Fire on the enemy at longer range and still be mobile. Don't expect any kills and withdraw the moment you are under fire. The assist points you gain is more important.
Tactics: Once you get the UAV up, it won't take long until the Care Package and Counter UAV comes in from the assists. With both the UAV and C-UAV up, you can chain multiple killstreaks over and over. Reroll care packages for another chance at a mid to high end killstreak.
Pros: - Can increase your SPM drastically - Support your teammates in securing the win by Denying Enemy Air Support, disabling their equipment and radar, call in UAVs and C-UAVs, and get a chance at a powerful killstreak. - Can potentially cycle through your three killstreaks over and over again.
Cons: - This is heavily dependent on your teammates not dying easily. - This also depends on your enemies using equipment or UAVs. - If you are stuck with bad teammates and/or lack of enemy equipment and airsupport to disable with EMP, then you must take more risks.
http://youtube.com/watch?v=Pm1ytVdzfkI&search=baby%20got%20back%20sir%20mixalot Warcraft Got Back
Also if your teammates are really good, you'll be doing nothing most of the time. That's the problem I found with the Engineer, EMP combo. Especially when they're spawn-killing, you'll die a lot when the spawns flip.
After trying that couple for awhile, I felt the Engineer and EMP combo isn't worth it, and I got better SPM by using a LMG + a couple attachments and perks and taking people out long range. Rerolling Care Packages is always fun just not on HQ or Hardpoint or when spawns flip.
Also I believe bouncing betties are too useful if you're using Scavenger. I can't create a class without betties.