Which slip-ons are recommended for a '09 Harely XR1200 with no other mods except an air filter and fuel programmer upgrade, and how many disks are recommended.

Looking for much better flow without too much added sound.

I'm a fan of Supertrapp and ran a 2-1 Supermegg on a '06 Softail and '06 Street Glide and now have the FatShotz slip-ons on a '12 Road Glide with FuelMoto 2-1-2 headers.

Looking for slip-ons for the XR1200 rather than the full 2-2 pipes.