It's not difficult at all. You have everything needed if you have the SE-R just lying around. You just need the motor, mounts, wiring harness, ECU, gauge cluster(just because it would be easier to swap it), and all the little accessories under the hood of the SE-R. For 5500, I would definately do it. You could also check out
http://www.sr20deforum.com and look around there for info.