I went with the Borla and i have no complaints at all, they have two models for the magnum, one is very aggresive when it comes to the sound and the other is mild. I went with the milder of the two, it's not loud but when you punch it the sound roars..! Check out their website,
Borla Performance Industries - Borla - The World's Most Winning Exhaust .
Hope this helps.
Chris
Semper Fi