You can do it yourself, especially if you're mechanically inclined. I ended up taking mine into the shop because I decided not to buy the mid pipes and knew that the shop has done many exhausts before mine and they wouldn't charge much to bend a few feet of pipe.
Regarding the chin, I suppose there's a possibility that it would come in black; however, when I ordered mine from American Muscle mine came in a light, crappy grey. It was no big deal though, I swung by wal-mart, bought a can of outdoor multi-purpose flat black paint (make sure it specifically says "plastics" under its list of uses), and just sprayed 3 even coats top, front, and bottom. It works just fine and I think if not a perfect match to the rockers, it's pretty damn close haha.
Man, I would love the gt/cs rear bumper, but when I just couldn't bring myself to pay 400-500 bucks for a bumper. Now I've got stripes, making that option even more expensive. I shoulda checked out ebay while I could've.