Anything will fit with moding. But a banshee shock doesnt work the best, mounts differently and lowers the rear end like 2 inches. A 400ex, z 400 or 250r shock would be much better.
i'm running a shee shock w/ +3 arm and it is perfect i couldn't be happier w/ running it. i can feel every adjustment w/ the compression and rebound. i already have a 400ex airbox on mine so i dunno if you have to mod the stock one.