Use the following class:
Lightweight (what I llike but use whatever is best for you)
Slight of Hand Pro
Marathon (I find it the best but use what you like most here)
G11 Low Power Scope or Variable Zoom.
Now this is Qs'ing because the gun will have a Scope on it, you will go in quick shoot and come out. Here is some game play of my cousin using this, Please subscribe to the Youtube in my sig and this one if you want to see some more gameplay of Qs with this and Qs with snipers. (in nextgentactics thread about quickscoping tutorial the gameplay is me)