I'd probably up the ante to a 31x10.50 for your 15" rims. These will work fine on a fresh 2" budget-boost. Increasing the bumpstop limits your axles ability to articulate upward, thus keeping the tire from jamming itself hard inside the fender. You may not need it, and I'd try wheeling it for a trip or two without them to see if there's contact, first, before rushing out to buy a set.
Eventually, as money allows, you will want to swap out the pucks with a good 2~3" spring lift. good luck - shoot us some pics of the final result!