Scotts Antique and Classic Car in Bassett, VA has 15x10 rally's...they are actually the Corvette style but they have them in 6 lug for GM trucks. Their web site only lists 5 lug versions but if you give them a call they will hook you up...I think the price's are similar too. Here's a link...
http://www.scottschevyparts.com/Show...y%20Wheel.aspx