Who said 2" was enough to clear 30's with no rubbing at full articulation?
You can run 31's on 3", 30's on 2", or 33's on 4.5". The trouble is to avoid rubbing, you'll need to extend bumpstops, and possible steering stops depending on the wheel offset/backspacing. This will seriously the jeep's ability and in my opinion, defeat the purpose. The other option would be to cut the snot out of the fenders and get new flares. I'm guessing you won't want to do that on your '00 XJ, but I could be wrong.
Joe - if it's going to be a daily driver and see light trail use it will be ok. If you want to take it and twist it up on the trails, get a bigger lift or get a smaller tire.