Re: steppers best?

I think it is worth a go, if speed is not essential then you can
pretty much just set the micro to produce x number of pulses which
will equate to a distance related to the gear ratio and wheel diameter.

For higher speed an acceleration and deceleration phase would be a
good idea, perhaps just a look up table in this case, adjusting the
coast distance to match the required destination.

But first you need a stepper motor driver that will work with your motors.

If the motors are bipolar and require less than 0.75 amps per phase
you might consider these:

http://www.sparkfun.com/commerce/product_info.php?products_id=8368

I think they look just the ticket for small automation and robotics.

Graham