hey daox...look at this
Mufflers - summitracing.com
the large body magnaflows are pretty quiet, especially if you get the dual offset...
also Borla mufflers are quiet too, but cost too damn much
they also have a roundie 6" dual offset muffler in 2", just like the one i was running on my car (but i run 2.25") i'd take a piece of 1.5" diameter straight about 15" or so long, then have it swedged up at one end to 2" OD to slip in the muffler for the tailpipe, the small pipe at the end will lower the exhaust velocity tune even further down the rpm range, & also help kill some more sound
unfortunatly the smallest we mandrel bend is 2.25, which is the smallest we do in stainless, or i'd help you out with a system (that fits :P )