This is a widely known issue with FWD SR20 engines. It seems that most of them spin the #3 bearing but #2 happens also. It's not a "daily driver" problem, usually happens as a result of high RPM plus oil starvation. The result is that most of us run synthetic oil and check it OFTEN.
If you want more info head over to
www.sr20forum.com and search for "spun bearing" or "rod knock" and you'll get a ton of hits.
Hope that helps.
FYI - you can get a low-mile JDM engine for under $500 (sometimes under $400) from Soko and a few other suppliers. They're usually quite reliable and most of them come from automatic tranny cars, so they're usually not beat-up.