Hi Pete,
You might consider boring the cylinders to 54.5 mm (466 cc) and using the Yoshimura piston kit. I'll have to check my notes but I believe this is a 9.6:1 compression ratio.
Also, as an alternative to the Carrillo connecting rods you could go with Robson Engineering connecting rods. They are just as good and are mfd in the UK. I'm guessing that you are on that side of the pond.
The Yoshimura pistons are 13mm wrist pin bushings, and the Robson or Carrillo rods are made to your specifications. I have both and they are equal in quality.
Sounds like a very cool bike you are building, I hope to see pictures. Maybe you could start a thread in the "Project Shop" forum so we can watch the progress.