sr20de could be badass, but just like an n/a KA motor, it will require a good chunk of change. and possibly some sacrifice in streetability...meaning high compression, nasty nasty cams, maybe individual throttle bodies. but at least its actually easier to do than an n/a ka, those seem to suck even when built n/a.
for a nice road course car, or maybe autocross it would probably be pretty nice. high compression, good cams and tune and ITB's...i dunno how much u could get out of it honestly, at least 200whp if not 225-230...plenty enough for a 2600-2900 lb car to do alright in. i think 250-300 is doable on those race motors, but i wouldnt expect it out of a street car.