square drive shaft is a good option. i did mine not to loong ago with 2 ifs ujoints...plenty of angle and plenty of slip.
a few times in here guys said they would never go dual cases. i cant see how a single 4.7 case would be better than 2 stock cases. you retain your stock low range, gain 2wd lo, and in doubled you're lower than a single 4.7. dual ultimates sometimes are too low around here, but dual stock cases, i think, give some of the best gearing options for overall trail riding. duals were cheaper than 4.7 gears for me too.