First off. I have replaced my oil pan. You can remove the oil pan without removing the timing cover. There was just this plastic thing covering the flywheel that hid two or four of the pan bolts. You won't need a replacement gasket, it is rubber, and I reused mine without leaks [after properly torquing it down, which is a VERY important step, it'll leak otherwise, and leak BAD]. I used some NON-HARDENING gasket maker on both sides of the gasket.. I found it may not help seal it, but it helps keep the gasket on the pan, because it isn't the easiest thing to keep on the pan while sliding it on. When you have the oil pan off, make sure that there isn't any rust on the pan, that the baffles are in tact and aren't falling off and that the oil pickup is securly attatched, the screen isn't damaged and that there isn't sludge all over it.
The rod bearings cannot be changed under the car.. it is much too tight to do it.. not to mention you have to pull the crank shaft to get both sides of the rod bearings, and it isn't going to be sanitary under there.. and I would suggest away from it.
'89 SSE - GX3 -190k, 155k on body - Back for another ride.