I've got one from clifford on mine, works great and wasn't any more pricy that what else you can find. Friend of min put a Borla on his, but with the header and complete cat back he was at close to $900.00 before it was over. It took him two days to do it, but then again he has no clue which end of a socket goes where. I've been told to stay away from the hedman brand, must be QA problems or they are to thin. ???
I have a borla, the install wasn't bad, it makes the 258 have a slightly higher pitch to it. We didn't do the cat back, just the header & regular exhaust. I can't say on performance because at the same time, we swapped about a zillion other things. It has help up well so far about 4,000 miles.
I would seriously consider what Jaffer suggested though.