3.0-3.5" max backspacing for full steering on true 37s like the MTRs normally. You will likely need wheel spacers on top of the wheels you find. Find a cheap 17x8.5-17x9 you like as most are a 4.0-4.5 BS (check discount tire they have 17s for the JK from $102 a wheel) and buy a set of 1.5-2.0" hub centric wheel centric spacers for $120-150.
If this is the case, I might as well just replace my steel 15" wheels that are trashed, and save some money on tires. I'm trying to get away from spacers.
It is very hard to find 17" wheels with less than a 4" backspace so if you want 37s and full steering you almost always need wheel spacers. You can have custom wheels made with whatever backspace you want but that is costly. Toyo makes 37s for 15" wheels if you want to run 15s.