Don't do an OEM
You'll be surprised at the increase in performance by just removing the OEM muffler. If you are not adding HP, simple muffler replacement, not OEM, but same pipe size will work well but if you've added HP or plan to, go to 4" turbo back, the tail pipe is 4". However, yes noise is the thing to minimize for some of us. If you'll look up the muffler discussions here there was one very interesting comment about 4" pipe with a 5" Donaldson, M100580, 51" long muffler. They said no noise!! Check it out, you might want to contact them before doing anything. I personally installed 4" with 2 Pinnacle Performance mufflers end to end and it's just fine running empty and gets plum quiet as it gets hot?? However, go WOT and the kiddies think it's sweet, it sure gets your attention. It does sound better than anything I've heard but just a little too much for me and it also growls uphill with the 5er on. I think the 5" Donaldson may be my nx move, I'd love to just hear the motor again. By the way I do have a new, never installed 4" down pipe from Geno's and a Silent Might muffler used 3 months that are for sale. Anyone interested, contact me.