Sounds like you have very similar goals with your MJ that I have with mine. For what it's worth I went 8.8 rear (factory LSD), sprung under. Swapped in a "large" u-joint hp dana 30 from a '97xj and got away from the CAD system, put a trutrac in the d30. 4.56 gears, 4.0, ax15, 231, 33s.