Chris... I think you may be screwed as far as the 3.0L (NSX engine) goes. I am pretty sure (99%) that engine will not fit in the Integra engine bay. Plus the cost of the engine, transmission, ecu, and all the many hours of custom work will be prohibitively expensive. Probably more than you just spent to buy the car.
If you do some more searching, and maybe post this in Engine Tech, you will get a more concrete answer (like the exact dimensions of the 3.0L or 3.2Ls, and why exactly they won't work)...
You're biggest problem is that they were designed for a RWD platform, while the Integra is FWD. To try and changeover the GS-R from FWD to RWD is sort of like getting a sex change and a heart transplant at the same time.... not advisable.
Good luck if you're really stuck on this project, though. Just remember, like TriDawg said, turbocharging a B18C1 can produce some nice fat power, maybe up in the same range as the 3.0L... !