Reeg set up that will bolt onto your existing stock hub. Red Baron is on back order for about 2 weeks and sano is not making anymore rear disc set ups. They said they are going to a foot brake back in Nnovember. I have not seen a rear brake set up from them since.
i know people are always lookin for disk brakes that you can use thte stock hub with and i found another company with em, storm cycles has em for pretty cheep at least i think its cheep