Who does diesel exhaust work??

I have 2 questions:
1. Does anyone know of a muffler shop or any other place that may have some 4" aluminized pipe running around?
2. I know a lot of you like Bryan Muffler, but does anyone know if they are competent enough to install a turbo downpipe?
I'd do it myself but I have no sawzall or torch or welder or patience and my genius exhaust guy back home decided that when installing a 4" exhaust system, the stock downpipe should be welded to the new system and the 4" downpipe somehow worked better in the bed of the truck. :confused: