EasyDriver Stepper Motor Driver by SparkFun - ROB-12779 - BC Robotics
SparkFun ProDriver - Stepper Motor Driver (TC78H670FTG) - No Soldering Required Power Supply Operating Voltage: 3.6 V to 16.0 V Allows Full Half Quarter and More Step Operation: Amazon.com: Industrial & Scientific
BOB-13752 - SparkFun | Stepper Motor Driver | Evelta