You know, if you're not too particular, Emgo makes a selection of cheap mufflers. You can see their catalog here:

http://www.emgo.com/emgo_catalogs.html

Notice the inlet specs, find a model that fits, then go to amazon.com to buy it. Yeah, Amazon. Who knew? Do a search there for Emgo. Most of them are in the $60 or less range.

Yep!  the Supertrapp was the best investment I made for my bike. Tons more power and I agree SuperRay. The best sounding muffler of all of them. No tinny sound just a good deep rumble that sounds cool when decelerating. I heard a S-40 with a jardine and it sound ratty compared to the supertrapp.