The car came out with an SR20 in it!!! Makes it easier..the Sr is a shorter motor. Run stock internals and better turbo, powerfc nd youll be set..
I think you can do better if you get an S14 or S13 front cut. Wack it in. You could make about 200rwkw on stock internals??
If you blow it spend $1k on another motor.
I dont believe the Sr20s are any more expensive than an Rb25.
If you really want the grunt - go the Rb25...