if your going to have some custom bent pipe anyway.. go dual exhaust hehe j/k thats a whole 'nother level of project... im hoping my stock muffler goes soon so i have a way to justify new muffler and tailpipe... heh

i'm no muffler expert but i have heard good things about magnaflow.... for mine i was looking at a dynamax (or dynapro... i forget the name) that is made for a 3.5L monte carlo.. its got 2-1/4 in and 2-1/2" out