Motion Pro and most of the "cafe" vendors usually have them in supply. Dime city cycles, the like. it will be advertised as for clubmans, drag, supermoto, -2", something like that. See what you need them shorter by after being routed properly with no binding lock to lock and go shopping
One thing with the brazing is you gotta use the right rod for it not just what you have laying around. I believe silver solder is the stuff, I'm sure someone will correct me when/if wrong