I think it was some front XJ Cherokee shocks that i tried in mine. They were for a 2" lift, and were at least 2" longer than my 1" longer-than-stock OME shocks i have on the rear of mine. I couldn't keep them on since they weren't mine, but they looked like they'd work.
I've heard the same about front TJ 4" shocks on the rear, or YJ might be the same as well.