What type muffler are you looking for? Stock? Performance? You should be able to goto a muffler shop and get one for $40 bucks or so and another $15 to get it welded on. If worse came to worse you can goto PepBoys and grab one of there generic mufflers that meets the space requirments for around $25 plus $5 in clamp hardware.
rcm, so you jut welded an aftermarket muffler to the stock exhaust? im still so torn with what to do for exhaust whether i shoudl spend the money and get the saab sport or get custom cat back 2.5" but then id have to find a muffler