Exhaust size?
Go to Summit or Jegs for the exhaust system. I used there 2-1/2 inch system on my Duster. It fit well and was easy to install with only minor tail pipe trimming involved. Cap them in chrome tips and your looking good.
They come with and without mufflers. With mufflers, I beileve I paid $200. Without mufflers, the savings is slight though you can then choose what ever muffler you want .
It is a true dual pipe system, no X or H pipe.