steppers best?

We (high school kids and I) are building a small electric car for a
competion. It must be 40 cm by 25 cm and be calibrated to travel
between 5 and 10 m. We'll be told the exact distance at the
competition. We have a VEX kit (and encoder for it), a Legos RCX,
small perm magnet DC motors with a PWM controller, and lastly some
salvaged steppers from a FAX. We could do something "crude" and use
some rev counter (threaded rod, fishing line wrapping on spool etc) to
turn the switch off, and coast to a stop, but I'd like to try
something a little more sophisticated.

I'm looking into being able to run the VEX without a radio control -
autonomous only, and then jumper, or have a set of DIP switches to get
various distances, but am not sure it I can run without radio control.

We could also do a timed drive with the RCX.

But I'm leaning toward steppers. We just salvaged some nice little
units from a FAX - 7.5 degree, 100 ohm, no torque measurement yet, but
I think they'd move our little car pretty easily. Our level of
expertise with steppers is that we can make them do single steps with
a 4 switch/diode test setup in David Benson's Easy Steppin'. So we
have a ways to go to get the 5 - 10,000 steps we'd need to get the 5 -
10 meters, and my questions are these -

1 -Are steppers our best choice?
2 - Is it pretty easy to do the microcontrolling effort to choose a
certain number of steps (DIP switches etc) and then stop, or is this
more like an iceberg - a lot deeper than it looks?
3 - Other considerations?

I'm the guy who was looking for the Allegro 5804s a month ago who want
to get something to "move" as one goal. We just learned of this
competition, in the last couple weeks, and it looks like a nice path
to take wrt "motion control".

Thanks