My best quickscoping class for pros:
Primary: L96A1
Secondary: Ballistic Knife
Lethal: Tomahawk
Tactical: Flashbang
Perk 1: Scavenger or Hardline
Perk 2: Sleight of hand(Why: because if your a good quickscoper you don't need steady aim)
Perk 3: Hacker or Marathon
Hope this helps!