I bought a totalflow from amazon for $40, honestly the best $40 muffler I've ever bought. the fit and finish was perfect, the steel was thick enough. Easy to weld. Lots of models to choose from to ensure it fit. Was exactly as described, dimensions were bang on. They have very clear pictures showing the guts so you can choose a model that fits your needs.
On my truck I went with a glasspack style but on the car I chose to use a more conventional muffler style but went very free flowing.
I wouldnt hesitate to purchase one again