The recommended phidgets controller does not appear to have any current limiting capability. If the coil resistance spec is right, I don't see how it can safely run the motor.
Maximum Speed of 118 RPM @ 12V
When running at very high step-rates, the actual current draw is limited by the the inductance of the coils. It could be that the 12v spec is only applicable at that speed.
High-performance industrial motor controllers with current limiting can use a much higher supply voltage to achieve higher speeds. At lower speeds, the current limiting will reduce the voltage to a safe level.
I just noticed this warning on the Phidgets page:
Connecting the motor directly to a power supply will destroy the motor and void the warranty. If you want to check your motor make sure it is connected to a constant current / chopper drive controller.