Before I make a mistake, what do I need to know?

I am a new member to this group, and also new to CNC, so I need a lot
of help. I have 3 Sanyo Step-Syn Stepping Motors, Type 103-820-2,
which are 4.5V, 1.4A, and 2 Degree/Step.
I have been searching and reading material on the net, and I am still
not sure about some things.
What I want to do with the motors is to build an all metal (aluminum
frame) CNC drilling (for printed circuit boards) and routing unit.
With the motors that I have, is it best to use them as bipolar rather
then unipolar motors which they are, just by not wiring to the center-
tap of the coils?
I am still unsure about stepper motor controllers. Is it best to
purchase a commercial controller or will a DIY one be adequate. I
want to power the motors with 24VDC-35VDC and use a "chopper" type
circuit. Also, there are different circuits for unipolar and for
bipolar.
Also, originally I had thought of just using a Dremel tool for the
drilling of small holes into printed circuit boards, but now I think
that the Dremel will be too light, especially if I want to do some
routing in wood. What would be a better choice in a high speed tool
to use...a higher HP router or a high speed laminate cutter?
What are the other things that I should think about in the design of
this unit before construction is actually started.....besides money :)