If you want something that's not in kit form, http://www.automationtechnologiesinc.com/products-page/kl-stepper-drivers/kl-4030-24-40vdc-3-0a-microstepping-driver should do the job for a little bit more money. They also sell the Gecko drives, so you can compare them.
One thing to be careful in stepper motor driver selection is that many sellers rate the drivers using the maximum current instead of the continuous current rating. This is a good way to burn out the driver if you exceed the continuous rating for more than a split-second.