You haven't mentioned batteries in your list of things that you will be having to buy either. You could use this drill ones, at least for now.

I think there is a tutorial on how to do that here: http://www.rampagingchariots.org.uk/abo ... out-us.php

Well, that is a photo of a way it can be done but there are manuals in the construction section on how they have done it.

You can always revert to wood, nails and sticky tape if it all gets too expensive haha