All you need is Suppressor and Extended Mags. Perks you'll need toughness and dexterity.
My favorite is -Suppressor & Ext Mags -Hardline & Ghost -Toughness -Dexterity -C4 -Concussion
I'd personally recommend fast mags, because the 10 extra bullets aren't worth the longer reload time IMO. Depends on how often you run into multiple enemies though, if you're able to maneuver yourself to a point where you have a second or two between gunfights then fast mags is the way to go.