That circuit is a very simple stepper motor driver that may be adequate for a small machine, but may not be suitable for a larger machine.
Can you provide more information about the milling machine that you intend to use?
The circuit requires a 6-wire stepper motor (or an 8-wire motor wired up for unipolar operation).
I know of many places from where you can get such motors, however they are all located in the United States. Perhaps someone else can suggest a local source for you.