Greetings!
I had an '08 heritage, and I put Rush slip-ons on it.... They have
several different baffle sizes to choose from to tailor the sound to your liking... Their website has some pretty accurate sound/video
clips. The quality seemed to be pretty good on the Rush as well. Powerful sounding, but not overwhelming.... Those kromewerks that rcsoftail mentioned are good, too.....
I also heard some Screamin' Eagle slip-ons with Big City Thunder Monster replacement baffles in them the other day.... very nice... maybe a bit loud for your situation, however.....