I did a CME center mount exhaust on my Blazer ... got it off Ebay and was once on a Camaro SS ... pics can be seen in the Exhaust Section

 

I wanted the 45* off the corners as well but it was a no go. With the tank being in the way as well as the leaf pack it would have been a miserable job trying to jam em in there. So i just went with em straight out the back almost to the ends of the bumper. I just got mine done this morning and got full stainless muffler (flo-pro i think) with 2.5" pipe into 3" magnaflow tips. I mean the corners COULD be done, but i haul a 6x10 trailer with wood and 4 wheelers and stuff and when my leafs compress it'd crush the pipe. Hope this helps.

Heres a pic of mine.