Looking for muffler suggestions

My 73 Duster/340 currently has TTI headers/exhaust (2.5") with the standard DynoMax Super Turbo mufflers. After driving the car, I have determined that performance mufflers are not for me (I didn't even look at them before ordering the system...oops!) and would like a quieter muffler.
Is anybody running a non performance muffler on the TTI system? What are good options to look at? I am planning on going to some local muffler shops and would like to have some idea what I am looking for before I go in.

Thanks!