They are cheap as he'll on eBay. As far as choice of muffler it depends on how loud or quiet you want it. I have the 22"long 5x8oval 2.5" dual in/out on mine and I love it. it is very quiet at idle,good rumble at lower rpms and wide open at WOT. I can hear my stereo over it at low volume which is a big plus. At 60-70 mph it is like I have factory exhaust. Still getting 15avg mpg in town with a heavy foot and around 20 on the hwy.