I'd say it depends on the shop whether they would charge more or less for supplying your own muffler. I had mine done at the same shop I had do past trucks back home so he cut me a great deal on the muffler and install. I have a single in single out setup with a dual tip exiting before the passenger rear tire. Cherry Bomb Vortex, I love the sound of it, no excessive droning to drive you nuts but a nice aggressive tone. The only droning I've experienced is at high idle when the truck is first started and still cold, other than that it's civil enough until you step on it. My tires will actually drown it out on the highway (granted those things howl like mad but goes to show the muffler won't drive you nuts on a trip).