Muffler advice anyone?

So I wrenched an aftermarket exhaust manifold off a P5 I found in one of the pick'n'pulls here in the city and after wrapping it its been great!! With fresh plugs fresh oil and drop in air filter I'm quite happy with the extra power restored after buying it with 115k miles on it. After reading some threads about exhaust I've come to learn that changing out the manifold is great and all at normal driving conditions but as you all kniw this car is all pep with a little step on the gas so I've noticed she bogs hard after a certain RPM so my question is can I just change out the muffler with a higher flow one cuz I'd like to do something with dual tip to stand out instead of a single big shiny can, almost similar to a late 80's RX-7 stock exhaust ??

Any tips advice or actual part lists would be super helpful thanks familia!!