Pete, if I did an ethercat gantry machine, I would use some high flex mains cable from Treotham to power the motors and either add a poe injector to put 24 v power to the motors or add a small 24v power supply (like Meanwell HDR-15-24) to power any motor IO. The motors have their own I/O ports for limits and homing. Then at the gantry, probably a 16 input /16 output module on the gantry for all the IO up there. SO basically, there would not be a control box so it would be a very clean streamlined build.

Ethercat adds complexity though!