1. How heavy is the shaft?
2. How long is it.
3. How do you intend to support it while balancing. Dynamic at speed I assume.
4. How fast do want to spin it?
5. Easiest way to drive it is a flat belt, and be able to spin it in both directions.
6. Will you remove or add material to achieve balance?
I class myself 'expert' in the balancing area, ego not withstanding.
I will be able to tell you what won't work.