slant 6 exhaust sound

im off to the muffler shop tomorrow to get new exhaust on my wifes valiant.i fabricated a split manifold with dual 1.75 outlets .the headpipes will run about to the tail shaft of the tranny and then Y into a single pipe all the way to the back.there will also be a commando style resonator added built form a polished 304 ss steel pack and an exhaust tip grafted together.......however im torn on the what to use for the primary muffler.i have a 40 series flowmaster on the shelf as well as an imco turbo muffler.any suggestions or sound clips if you have them would help.thanks.