Because I cannot get any of my projects working I decided to start another in the hope I would succeed and get my inspiration back for my other projects, so naturally I am now stuck, a common theme

My new plan is to build a leadscrew controller based on the Clough 42 project:

https://youtu.be/FTs9GygRQ-U

I have bought a good few bits but I am now stuck on my choice of Servo/Stepper to drive the leadscrew, my plan is to drive the leadscrew from the tailstock end thus getting around any gearbox issues, the lathe is a Harrison M300 so not Chinese Micro Lathe territory.
I would be very grateful for any and all suggestions as to what size/make/power of Servo or stepper motor I should be looking at, it is going to need to be of a decent spec because the leadscrew is 28mm diameter and 6mm pitch, so not lightweight.