I'm running 37" tires with flat fenders on a 3.5" RK Long Arm lift with no clearance problems, but if you are wanting to go that high with a lift, I'd go with the Rock Krawler 5.5" lift.
Here is a couple of links for the mid arm lift that uses the stock control arm mounting points JK 5.5 X Factor System
and the long arm JK 5.5 X Factor Long Arm System
that requires more work, but a long arm lift is really the way to go with a lift that high.
If you go that high, you will probably need drive shafts and a few other things too for everything to work right.