I had an '86 si, and went to a junkyard when a tooth broke in reverse. The used trans was supposedly the same one, but guess what? It wasn't. I didn't know until after I put it in (they look about the same, so the junkyard could easily get it wrong). But once I got it in, I decided to drive it that way for a while. It wasn't that bad. I still don't know which tranny it was, but I found that I could go 160 mph (for all the good that'll do you). Yeah, you really have to wind it through the gears to get good acceleration, but at least I didn't have to hear the engine screaming as I drive 80, since it's only turning 3,000 rpm (3900 with the old one), and that's in fourth gear. I actually found that I preferred it. Something in-between would be ideal, but if you plan to drive the autoban, this is the tranny for it.

As for the bearing problem, I'd fix it. I've owned 4 early CRX SI's, and I find that they need a new main bearing around 200,000 miles. I replaced the bearings myself. You can actually do it without removing the transmission from the car, but it's probably better to remove it. But having done it twice now, I'm going to try it in place next time. Watch out for the Honda dealerships though, they always sell me the wrong bearing.