Stepper motor and driver - info needed

I want to try to automate the wire guide on my inductor winding machine.  I currently have the guide on a threaded rod with a wheel on the one side which I turn by hand to move the guide.

Although not audio-related, the inductors are audio related, and I know there are a couple of guys on the forum who would be able to assist me with this.

I want to get a stepper motor, and be able to drive it via USB port.  If I have to write some software to control the motor it shouldn't be any issue - I used to be a software developer in my previous life.

The reason I think I need a stepper motor is because of the following:
1.  I use different guage wires, so there is no "standard".  The thicker the wire, the faster the guide needs to move in proportion to the spindle.
2.  When the guide gets to the far edge of the inductor, the guide stays stationary for 2 revolutions:  The last winding on the previous layer, and the first winding on the new layer.

Now, my knowledge is pretty much 0 when it comes to these stepper motors, the size I will need, what kind of controller board, etc, etc.

If I don't need a stepper and there is an easier way to automate, please share your insight with me.

I appreciate the assistance.

Regards,
Ian.