American Muscle. The first one I bought was Shaftmasters. 3.5" one piece aluminum and it seemed great. During the winter, Shaftmasters bought them back because 2 broke on a dyno after being unloaded at somewhere around north of 140mph IIRC. I figured they'll give a full refund and none of the Axle Exchange 4" shafts had broken (These are sold by American Muscle as their house brand but are manufactured by Axle Exchange)
It cost a little more than Shaftmasters, I already had a loop and I knew I wanted the shaft installed so I just took the money I got back and put it right back into another shaft. I think it's worth noting Shaftmasters provided great service and has since revised their shaft to prevent that failure from occurring. The timeline wasn't right for me and I needed the new one (when I bolted on drag radials earlier this year) to run as safely as possible. I wouldn't hesitate to buy from them again, FWIW.
I bought my wheels and drag radials from them too. With a forum member discount you can't buy them off the truck for what they charge, shipped to your door and since you're not in PA, no sales tax. MT ET Street Radials for $203/each. Nitto NT05R (Pays contingency for drive wheels only, MT requires all 4. Bastages.) were 185 each.
The wheels were ~100 during a sale event. I bought based on looks/weight and just happened to get a good deal. You know, if you ever got out to the track you could see them in person.
And a video. Maybe this will finally stir up some interest in getting your car on a track where it belongs.
http://www.youtube.com/watch?v=YQsxsCj1wYY