Choptop is correct, the tires on that skinny of a rim will never wear right, and you will prematurely wear them out fast and be disappointed on the few miles you got out of them.
If you went with really skinny 35" (if you can find them), I think you will be disappointed this time on how they look on your truck. Better to wait or do more searching for something better.
Another note you should consider. Some trailer rims are not DOT approved for anything but trailers, so you should make sure and check into that.