I went ahead and ordered a new can for my bike. I know that some have said the stock can works about as good as anything if you are going to keep the stock headers but the cheap SuperTrap muffler that I put on was a vast improvement in the mid range and top end so I went looking for something that sounded better and still gave me that extra torque. It turns out that the ProCircuit T4 for the XR650 fits pretty well and has a great low end sound that I was missing from the obnoxiously loud coffee can sounding ST. It just barely fits over the stock header. You may even have to clean the parts up with some scothbrite to get them to fit together but it does work. The rear mounting point ends up being too high to use the stock foot peg location so I just cut it off to the right length and will be welding a new mounting bracket onto it.
Cheers