Depends on what IS200 she is, the IS200 Sports have an LSD fitted, but they are fairly light on BHP. Your best bet is the Beam's Engined Altezza from Japan. A 4 Cylinder 270 Brake [i think] screamer..
Not sure how helpful this would be but i'm pretty sure there are supercharger kits available for the uk motor. From what i know they RS200's are pretty popular for drifting in Japan though.