123d Printer Buzzbot MM-1.5 kit or complete printer comes with the fully assembled Sanguinololu 1.3a programmable processing unit with USB2.0 connectivity and (4) assembled A4988 Stepstick Drivers (the two z-axis NEMA17 motors are wired in parallel, so only 4 drivers are required)

Sanguinololu Electronics: http://reprap.org/wiki/Sanguinololu

A4988 Stepstick: http://reprap.org/wiki/Stepstick

Allegro MicroSystems Inc: http://www.allegromicro.com/Products/Motor-Driver-And-Interface-ICs/Bipolar-Stepper-Motor-Drivers/A4988.aspx