I cannot help with a shop, but recommend you call Spartan for a chassis/front end shop. I had a similar problem and Spartan recommended a shop in Mesa Arizona for me. That shop found that the rear duals on the curb side were misaligned by 3/8 of an inch causing me to push down the road wearing tire edges. I would suggest that you have a front and rear alignment and also check your weight on each tire position and axle. Depending on wear you might want to rotate the tires from the front to a dual, that's what I did.
Good luck and let us know the outcome
2008 Jeep Sahara '4Dr"