Need expert guidance on rookie DIY build.

[Steeki]

So what do you want to know because you haven't exactly asked a question other than saying your not sure which linear system to use.?

I would like to know if a Nema 23 stepper motor is the right choice for this application, and if so, how would I attach this to my 32mm diameter spindle? Also if I could get some advice on whether to turn this a-axis with belt and pulley system or chain and sprocket?

Cheers.