just go to any muffler shop. they can just crush bend some pipes for you. if you get an exhaust from them as well and its a good one a cat-back should cost about $200 or so. just really depends on how much the muffler costs b/c thats what will cost the most. i had a flowmaster one for $120 from them and they charged me like $180 all together. but then again i knew the guy so he gave me a discount.
Sweet... Cuz my exhaust was bent up when i bottomed out... and now instead of getting a stock one, i was thinking something like a nice new piping, and a magnaflow muffler...