| Welcome to the site! Custom pipe work: There's a muffler shop called Mad Hatter's that does custom pipe work, but I'm not sure if its mandrel bent piping or crush bent. LJ can tell you more about them and their work, he had a custom exhaust from them.
As for axel back exhaust: I have the HKS Hiper rear section. It looks good, better price vs cat-back. From what I hear the gains are good, and I didn't loose anything on the low end (torque). The only possible down side, I can think of.... its kinda quiet. But that works for me, because I didn't buy it for sound, I bought it for performance.
Hope this helps... | 
