You used to be able to get the numbers from the Australian company MetalGear, but they don't share this info any longer - but they do post pics of their discs. Here are 2 options that, dimensionally, look like they have the same 5 bolt pattern. They all look like they have zero offset and are floating discs, so I say here are 2 options to look closer at. The 01-05 FZ1 1000 really look promising except the stanchions are 43mm.
Are you going to make a spacer to offset the R3 caliper to the new disc or will you use a different [fixed] caliper and spacer?