I just did a set of these a few months ago. Here's the centers I used. They worked great and were a really great product. I just plasmaed the old center using the ring as a guide. Then I cleaned the lip on the back of the wheel and tapped the new centers in with a punch. I tacked the centers in and threw it on a tire balance machine just for fun. They were all within 2oz.
http://www.cmperformancemachine.com...essed-Wheel-Center-w-8x6.5-Wheel-Pattern.html
I also put rim stiffeners on them because I have bent too many wheel lips, plus mine were 8 bolts which seem to be a little thinner. These are the ones I got. Mud is a great guy to deal with.
http://www.mudprometalworks.com/8bohuwhrimst.html
I have to say I'm really suprised at how much they weigh. They are EXTREMELY heavy. They are about the same weight as a steel wheel and 35" tire together!! Another thing is I thought they were going to be cheap. I wound up with close to 600 bucks in mine. For that I'd just buy some Allied's and be done with it.