Thanks for the replies. Very useful! I thought that cable would be fine but good to have it confirmed.

A_Camera - Your PSU looks good! I'm using Mean well SDR units to power multiple drives.

In terms of ground, the case itself is grounded using the mains ground which goes to a star point. All of the signal cables then have the shield grounded to the same star point inside the case. The only difference now is the DC power going to the drives on the motors rather than the stepper drivers inside the control box. I was previously using stepper motors but am now using these integrated servos instead.

I wasn't going to shield the DC power going to the integrated drives, just the signal cable.