X2talk to Billy at Stainless Works! Twinturbobilly on here!
Try Cone Engineering:
http://www.coneeng.com/collectors.html
I used of set of these on my new single turbo SBF set up and they are doing just fine. They are substantially cheaper than Burns. We are also using a set of these on the twin turbo BBF.
I used Burns on my old set up and they also worked great.
-Mikie