I found these boards on ebay, and tried to google the crap out of them but i can only find people using them for tiny stepper motors. will they work with the larger stepper motors like the ones found at sparkfun?
I think the easystepper ought to handle it - check the winding resistance is the same. What are the dimensions
of the motor - similarly sized steppers tend to have roughly the same power (I-squared-R) ratings since often
the design is thermally limited.
Although the EasyStepper claims to go upto 0.75A it will run mighty hot at that level from what I can see
of the specs - start at a smaller current and work your way up checking the temperatures are sensible.
Count the number of wires.
If you have four it is a bipolar motor and so needs two h-bridg circuits to drive it.
If you have five then it is a unipolar motor and each coil can be driven single endedly by pulling it to ground like the eBay driver.
If there are more wires you can often wire it up as either.