If you plan going turbo, get 3" so you don't have to upgrade later. Honestly I would get a cheap exhaust off eBay. Look at it like this: A pipe is a pipe, is that $600 exhaust REALLY going to get you that much more satisfaction over a $160 eBay one? Mine was great for about 2 years, then the packing blew out of the muffler so I cut it off and scored a 3" Apexi' N1 muffler off craigslist for $80. My eBay exhaust might have taken awhile to get it to fit correctly, but now it is exactly how I like it.
If your a pu$$y and don't want dirt under your finger nails get an expensive exhaust and fitment should be great so you don't have to touch it again.
PS: This is all opinion, don't get your panties in a bunch if my post is offensive to you
