Dexstar wheel has 15x6, 16x6, and 16.5x6.75. They're OE style rims that'll fit factory hubcaps. They're listed for "trailer use" but I'm sure they'r more than stout for truck applications.
I'm sure you need the wide rims, for bigger tires, after all this is the 4x4 section. I thoght I would just throw something out there.
http://www.dexstarwheel.com/products.pdf