John,
I have tried virtualy every opion for spinner drive and after much experimentation I have come down to usig 6mm pitch HD Stainless Steel roller chain for the fetherweight and dual SPA V belts for the heavyweight
I have another F/W spinner under costruction that uses a 5mm pitch 9mm wide HTD timming belt. This was chosen because of the velocity of the drive train and complex belt route. HTD belts are good up to 80M/S! were 8-10M/S is about the fastest I would comfortly like to run a chain.
As for ratios, I use 3.1:1 reduction in the featherweight, 1:1 on the heavyweight and 4:1 on the new Featherweight.