Contraptor

I'm about to try these: http://www.xylotex.com/StepperMotor.htm (Nema 23 Double Stack/Double Shaft Bipolar Stepper Motor)

I'll let you know how it goes.

They might be too big but I believe I'll be able to get some speed with them.

I'll post some video as soon as I get my first machine going.

With any luck, it will be this weekend or the coming week.

Hello.

Yes, it is too big, The pololu driver can only deliver 2A ( as it says in the page ), and to get full potential out of the stepper you would need a driver with more power.
It would work however ( ie. the pololu driver won't fry :) ), but you're wasting money in some sense.

You can easily find steppers rated 2A, that will fit perfectly with the pololu driver ( some hints above, also alltronics++ ).

About overheating, that's not a problem, you just need to cool it down ( ventilator works fine here ) if you want the put it at max current ( it will shut down if too hot, so no risk frying it here either ).