I personally haven't done an engine swap, but I've heard that you have to get a new tranny, ecu, wire harnessess at some other stuff, check out
http://www.sr20forum.com, they'll have a little more information. But I've heard that it is something you can do yourself, if you're pretty handy w/ machines and tools. Oh and
www.nissanperformancemag.com, might have an article on it. Good luck, post your results.