Just having a look at the centroid Acorn kit and its not too bad price wise but probably a little more than I can stretch at the minute.

The UCCNC looks to be a good option with good reviews considering the price.

would this combination get the mill running:

3 of these: https://www.cncdrive.com/DG4S_16035.html
1 of these: https://www.cncdrive.com/AXBB.html
Software: https://www.cncdrive.com/UCCNC.html
plus one 5VDC and 24VDC power supply
and the three motor encoders

Think I'm finally getting my head around it thanks to you guys!