it will have to be custom.

easiest way is to buy the 3" u-bends and flanges and have someone with a welder mock it up and weld it for you, or a shop. chavez motorsports seems to put out good fabrication, and i know taylor welds too now i think (he's at zfever).

if you want to save on "custom" parts, get a greddy or other SR style downpipe and test pipe and your exhaust, then you only have to fabricate the section between the turbo and the greddy pipe, basically an upside down "J".