The best muffler I ever had (bang for the buck) was a Magnaflow XL stainless I got off eBay for $59 shipped to my door. I had it on the Integra I ran in autox last year and I was very impressed with the sound I got out of it. I had a custom 2.25" catback with a 24" resonator and that mufller which resulted in a sound just a bit louder than stock with a nice throaty "growl" quality to it. I am going to use the same muffler on the XT6 when I get it ready for the autox this year.
Just do a search on eBay for Magnaflow XL and find an application to suit your needs. They even come with tips pre-installed for a few more dollars if you are interested.