If you are on the east coast, there is a guy in York, Pa., who often posts OEM takeoff wheels and tires for good prices. He gets them from Quigley (also in York). That's where I got my OEM 16" alloy wheels and Michelin LTX tires. His ads come and go. Here is his current one: http://lancaster.craigslist.org/pts/4859233852.html
Hankook 245/75-16 tires on steel wheels for $600, or Michelin LTX 225s on the alloy wheels for $1050. The Michelin setup is a particularly good deal, as those tires alone go for $200+ each, not counting mounting and balancing. It's like you get the OEM Ford alloy wheels for free.