Go with Nameless. I have the cat-less front/over pipe a Helmholtz resonator and the offset axle back with the 5"x6" mufflers and it is pretty quiet until you get on it. Nameless Performance makes their axle backs with larger mufflers now, I believe, so I can imagine it would be even quieter. Reasons: They seem to make some of the higher HP numbers on the market (I could be wrong), the quality is superb, it's made in the PNW, it's fairly priced, you would be supporting a small business, sounds great, I'm sure there's some I'm missing. Talk to @
Jason@Nameless he could tell you more about it.