[GM man]

I've noticed that there are fewer offerings out there for 15's, but I think they'll always be available. To each their own, but I'm a Goodyear man so as long as they keep making 15" tires, I'll stick with the 15 x 8 GM truck rally's, which I think look like they were made for these trucks.
There are so many wheels to choose from, but I think our bolt pattern is for 5 lugs: 5 x 50in (5 x 127mm) and 6 lugs are 6 x 5.50in (6 x 139.7mm).