I put a Sportster muffler on mine.  It was original equipment and all but brand new.  Since it has baffles you don't have to re-jet the carburetor if you don't want to.  I did buy mine on E-Bay from flightsimshop AKA kwikbay, but I'm told that many members here have found him to be very unreliable.  I got my muffler from him but it took much longer than I expected.  Otherwise it has been a good modification.  It gives a much deeper richer tone than the OEM muffler.  I'm sure you can find other vendors......

I think my muffler came off of a wide glide Harley.  I knew a friend with a bike and asked him if he had one laying around, turns out he had two.  He gave it to me and a heat shield which I cut to fit and cover up the joint.  He told me he had never heard that muffler on the bike, he got some freebie cash and had mufflers put on immediately.

I have read that harley shops will give you whatthey take off for free, but the shop here said they could not do that, company policy.  I thanked them and left.

Here's the link to my story:
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1244666206

Hope that helps  

If you are after the best performance, drop the $$$ & get a Supertrapp. If you want some improved performance, a better sound, less weight & a better look, my choice is the Dyna muffler. Very trim shape. On a small bike like ours, I think its the best looking muffler out there. I went with the Supertrapp, because my goal was max output, not sexiest looking. but, the Dyna offers better sound & performance for very low $$$.

I have a muffler off of a Dyna Super Glide.

One thing to watch out for is the ID of the muffler is 1 3/4 and the OD of the header is 1 5/8. Hard to get a good seal with that difference. You'll want to:
a) use an adapter
b) use a shim
c) use muffler sealer
d) some combination of the above

The previous owner tried b, didn't work.
I went with a+c. Cost me $20 to get a local muffler shop to fab up an adapter. If you go this route, have them put a slight (7-10 degree) bend in it.

-D. Dwarf

I went to a HD dealer and bought a used Sportster muffler for $25.00 and since I wanted to run the pipe past the back wheel break adjustment I had a muffler shop cut , flare and bend an exhaust pipe and install muffler for $20.00.  It works great a very soft sound not like the after market Sportser muffler I originally put on which was so loud I had a neighbour threaten me with piano wire!!!  
DocNeedles