JK axles are wider and aren't viable swaps for the rear. For 37s I'd be looking at an 8.8, D60, or 9". Front axle is going to be much more difficult though for 37s. A high pinion D44 would be a good axle or a fab 9" or D60.
If money wasn't an issue I'd go with fabricated 9" front and rear with true Hi9 third members. An 8.8 and HPD44 however can be a very solid combination for 37s.