You can try 4wheelonline. They have some good prices on XD's, Fuels, KMC and RBP rims-- http://4wheelonline.com/RBP_Truck_Wheels.104547. You can also find good deals on ebay.
I also have the XD's but I bought them from http://4wheelonline.com/XD_Wheels.67249. They have good prices. I recommend that you check different online shops to get the best deal.