I believe Stockton Wheels does it. There's another company out there that makes custom stock appearing wheels too, can't remember the name right now. Also might want to check out Wheel Vintiques to see if they make any 6 lug wheels, I know they make 15X10s for 5 lug trucks(I had some).
EDIT: Just found this a couple threads down. http://www.weldcraftwheels.com/ I've read a lot of good feedback about them.