Trig:
The motor is rated to 3V 2A, but from what I've read on many forms/sites they should be run higher, 12 - 24V even. Bad idea?
Hopeless idea. The windings are 1.5 ohm and want 2A for full torque. 24V would mean 16A and a small explosion and fire.
Perhaps you are thinking about using a bipolar motor chopper drive, which provides constant current drive for a low-impedance motor from a high voltage supply? In that case you'll need a driver that does this, such as the A4988, L6208 among many others.
This method allows much faster stepping since the whole voltage of the supply is available, if required, to overcome back-EMF.