Ris & Mind Bender are junk. The front right yfz 450 caliper goes on with little work, laeger posted a 4 piston old school street bike caliper that required some custom parts. The 250r is also gonna require lots of custom parts as well.
Cuervo Racing has a new kit for the banshee that happens to come with everything to be bolt on. It is a BREMBO opposing piston caliper, stainless line for your requested length, proper caliper plate, and any needed hardware. It's Tits!