A 95 R2 would probably be the best due to the suspension upgrades. It is not the lightest though. A base model is slightly lighter. 94-95 had glass sunroofs (moonroofs?) as opposed to the 93 body-colored sunroofs.

Actually, in answer to your question more directly, I wouldn't make the year of the car a major condition on buying it. I would start by looking for a clean body and interior. Once you've found that, then have the motor checked out. The year of the car (and even the trim level) would be far down on my list of considerations.