Motors are NEMA17 steppers:
http://www.ebay.com.au/itm/0-9deg-Ne...-/171937193275
I went with the DIY Arduino 2560 version, with DRV8825 motor drivers, rather than purchase a pre-made version.
link for more info:
https://www.astroeq.co.uk/tutorials....hp?id=buildown