Hey JMack, converting to full dual exhaust is not a big deal.
I had an exhaust shop do the conversion, with all new pipe from the Cat-Back for $250. Cdn.
Since I wanted to preserve original piping/muffler/tips for posterity, I had them weld new round stainless tips that really look aggressive and made a statement.
Without the muffler, the sound had too much of an edge so I went back and had them take a 12" piece out of each pipe and weld in some free flowing converters just behind the tips. This took the edge off the sound and was little more mellow. The beauty of this is that the exhaust system is freed up and the rear-end look is clean, no boxy muffler to see, only to round pipes well spaced between the bumper opening. Remember those Cosworth Ford engines back in the late 60s and early 70s with the twin pipes coming off the back.
I'm trying to upload pics but have no luck other than my signature pic so far. As far as the .wav sound, I will need some suggestive advice for that. I love cars and computers but not an expert in either.