My classes are constantly changing, but if I had to settle with 7, they'd be as follows:
All would have Toughness, Ghost, and Tactical Mask, with noted exceptions
MSMC - Long barrel, quickdraw / Frag Grenade, concussions ; RPG
LSAT - Quickdraw, FMJ, target finder / Bouncing betty, x1 concussion ; Combat knife
DSR - FMJ, ballistics CPU / Bouncing betty, shock charges ; B23R
Remington - Long barrel, laser / C4, concussion x1 ; B23R - Long barrel
PDW - Long Barrel / Semtex, x1 concussion ; Combat knife [Ghost + Flak jacket - for objective games]
AN-94 - Quickdraw, quick mag / C4, concussions ; RPG
MTAR - Quickdraw, ACOG / Claymore, shock charges ; FHJ