Project Bike: Dad's XT500 - Sourcing brake parts

I took another trip over to Zdeno Cycle to find some braking components. I picked up a pair of 310mm floating front brake rotors off of a 1996 Triumph Trophy 1200. It took me a while of sifting through the 'Rotor Room' at Zdeno to find a good matching pair of rotors with a mounting bolt pattern that would sit outside of the wheel bolt pattern. I'll only be running one front rotor and I'm going to use the big 310mm rotor on the rear so that the caliper will sit over the sprocket.
I also picked up a rear brake system - master cylinder and caliper off a 2006 Suzuki GSXR 1000. The caliper looked perfect - nice and small and the 2 bolt flange mounting.... But once I got it modeled and stuck into my rear wheel computer mock-up it became apparent that its too wide and will interfere with the cast spokes of the wheel... See image below. Now I need to find an even smaller rear caliper - maybe a motocross style with a single piston.

Well that's a bummer....

The Zdeno 'Rotor Room' - just a couple rotors

Rear brake donor bike

Rotor donor bike