Go with 37s! The JL Rubicon turns them without any issue. You'll get extra clearance and they look good. They are pricey and heavy though. Your MPG will suffer, but it's a Wrangler!
After installing a Rough Country 2.5" spacer lift, I've noticed that when coming off stuff the rear end slams. I double checked the shock extensions and they are on correctly. Anybody experience a similar issue?