Hi can anybody tell me a stepper I could use for a rotary atachment

Hi can anybody tell me a stepper I could use for a rotary atachment for the K40 or how to pick up on the moshidraw board to add another stepper driver as the standard driver will not take just any stepper it’s a 1A stepper I am told but I’m open to listening to anything you have to say on this matter. I see ready made rotary attachments for sale but they say that the K40 needs a larger driver.
Thanks for any help.