Kb has their own cai. Looks like crap but it works. Otherwise, any of the cai kits that fit a 2V will work with the KB also. I used the steeda cai on mine.
The KN CAI is hudge 4" and plastic. It won't heat up the air like a metal "CAI" and dyno proven to have no retrictions at all (giving about 30rwhp with TB and MAF over stock). I wouldn't think the steeda gives as much with metal and 3" (?) pipes...