there are tons of mufflers out there check out any local shop to get one that fits ur asthetic taste, and just make sure it doesnt have extra resignators at the tip, to avoid that tin can sound remove ur typical resignator off the straight pipe, DO NOT REMOVE UR CAT. 2.25 inch is fine for most applications, 2.5 is typically for forced induction and can kill ur backpressure on a n/a car so u can actually loose power on the low end of the power band.