exuast system

I am trying to set up an exuast system on my 78, ive got some old headers off of my 79 camaro and im ordering a kit from http://www.autopartsauthority.com/performance_exhaust/chevrolet~camaro~dual_exhaust_pipe_kit~dynomax~par ts.html .. i was wondering what mufflers i should buy because i want my car to sound even more bad ass than it did before. thanks.