Thanks again Clive, I'm inclined to go along the 7i76e route as it's a bit more compact and can be quickly plugged into different computers.

I take it that only inputs required for this board are the ethernet cable and a 5v power supply? My set up will be using conventional mechanical limit switches, VFD for spindle speed, 3 stepper motors.

It looks like this board can handle a great deal of limit stops - which I may want to try and handle the strange way the vertical axis of my machine can be positioned.

David