yeah man I recommend twin loop design, jdmcarboy.com sells the muffler for 125$ shipped and heres a clip of one.

http://videos.streetfire.net/search/...0701639fa3.htm

an example of a similar motor revving with a twin loop muffler, I think it sounds as good as a 4 banger exhaust can get, I plan on getting one, i'm just not sure of jdmcarboys inlet/outlet measurements.