Primary: ACR Silenced (for medium-long range)
Secondary: AA-12 (for clearing large rooms)
Equipment: Claymores
Special Grenades: Stun Grenades
Perk 1: Scavenger Pro
Perk 2: Stopping Power Pro
Perk 3: Ninja Pro
Harrier Strike, AC130, Tactical nuke. I find the AC130 to be far more affective than the chopper gunner, because it has more flares, more blast radius, and (at least for me) Javelins can not lock onto it. Occasionally if I'm feeling lucky I'll swap a pavelow for the Harrier

.
And if I'm playing bypassed, I will use:
Primary: Fall Spas-12 w/ grip & fmj
Secondary:ACR Silencer & fmj
Equipment: Sleight of Hand
Special Grenade: Gold Desert Eagle
Perk 1: Scavenger Pro
Perk 2: Stopping Power Pro
Perk 3: Ninja Pro
Pavelow, AC130, Nuke