If it's the honda, I know where there is a stock one sitting at a car dealership if someone is interested. I asked the sales guy about it and he said it belonged to the owner of the dealership and might be for sale. I never followed up.
Oh and I was planning on following the same basis, either a Busa motor or GSXR1000, chain driven solid rear axle like the way shifter Karts are set up.