Terry,
There has been some discussion over the years but to date I've not seen a successful shaft driven bike. The concept certainly isn't new. BMW started it years ago. Indian built a shaft drive motorcycle for the Army to be used in the sand during WWII. I have a friend who restored one.
You're correct in that the components would have to be beefy, maybe heavier than what your link bike has but the idea is sound. It would make an interesting project.
My guess is that the construction of the mechanics would depend on the rider's style. A guy who just cruises and never abuses his bike could get away with lighter components whereas the heavy hitters would need some stout metal in the build.
There are industrial parts out there that could be adapted for the purpose. Even good old Grainger could be a source for the gears and shaft material.
Tom