Feral4Mr2 is the guy to talk to, the turbo manifold he is working on now he took photos of and its looken real good, he used 12mm plate and t T pieces and 2 90 degree bends.
That site shows a picture of his MR2 setup, when he comes online im sure he will link the good photos he has, i cant find them right now
Ill be embarking on this my self, fabricating dump pipe and exhast manifold (not as loggy as a log, not as tuned length as a tuned length) my self. Welding is a very usefull skill when playing with cars, what better way to learn
The other option is to get a kit from japan or a custom fabricated ~$600-$1000