I'm going to date myself horribly by knowing about these guys, but here:
Skyway wheels
Mind you, anything above 10" is spoked, so you'll have some durability issues there. Also, interfacing, while possible, might be tricky. If you get one of the hubs bored for a 1-1/8" bearing, you should be able to press/slide a Vex VersaHub in there. That combined with a 3 or 6 spoke wheel and some creativity should get you an interface solution.