I've got 3 of those cncdrive drives Dean mentioned on my larger machine, If you have a brushed motor with an encoder, these will work and they take a step/dir input. I'm driving mine with a Centroid Acorn but an SZGH would dohttps://www.cncdrive.com/DG4S_16035.html

They are based in Hungary, so no tax or duties on the way in to the UK.