I may have to start riding to work early in the morning so I need something quiet that won't wake up the whole neighborhood.  I'll trade anyone a stock unmodified muffler for this one.  The muffler is about 65cm long,  rattle can painted(/high heat paint), and the inlet is standard HD size so it is a little big.  The sound may be just a little on the loud side, but its deeper and quieter the straight pipes.

there are alot of stock mufflers on ebay and the marketplace of this site.

you can do like I do in the morning... I roll down the hill until I'm away from the house and the fire it up.