Those seven-inch stock wheels are pretty much useless for larger tires. Eight-inch wheel width is good to about 32 - 33 inch tires while nine is typically recommended for 35 and 36s.
Rock crawlers often select a smaller wheel. This keeps the tire from popping off bead at low psi and the sidewall bulge will keep the wheel better protected from rocks.
Aluminum wheels are lighter but will break when abused and trail damage is more apparent. Forged aluminum wheels alleviate these issues but are relatively expensive.
Steel wheels are cheaper and can be bent back into shape out on the trail.