cant beat all wheel drive? that is so possible! an SR20 AWD against an SR20 2WD exact same motor and engine power output. Provided the 2WD can keep traction it should be quicker than the AWD. Less power drain through the driveline, hence more power for each powered wheel.
As for the kit being bolt on, i would imagine there would be minimal dramas with the whole left/right hand drive. the engine is still in the same orientation.