Rush
http://www.epiflex.com/ makes some nice slip-ons, available in baffle diameters ranging from 1.5" to 2.5". They even make them to fit the RH TD header pipes which are larger in diameter than the stock headers. On the Rush, if I didn't want too much noise, I'd probably stick to the 1.75" or the 2". They are available as a one piece muffler, or a two piece, and you pick the end cap that you like best. I personally prefer the two piece look. The "quiet" baffle for the RH's is a waste of money, from all reports I've heard. The RH TD pipes will be a lot louder on your stroker motor than on a stock 88" motor, as has been mentioned. I have the RH's on my 103" motor and they sound great, but they can put a ring in your ears at the end of a long day on the road, even with a full face helmet on.
A recent popular pipe is the Fat Cat 2 into 1 with quiet baffle...good low end torque and not too loud. It's a two into one, but you can get a ghost pipe if you must have the dual pipe look from the rear of the bike.
If you're going to do this, I'd go ahead and put a high flow air cleaner/backplate on the bike and get it tuned with either the SERT or PCIII, depending on what your tuner is most comfortable with using (and whether your tuner is worth a chit). The bike will run cooler with more fuel than the stock ECM configuration, which is REALLY lean, and if tuned properly, you will get the maximum performance and drivability.