Busy Bee retrofit ?

Hi, I am looking to retrofit a busy-bee milling machine:
http://busybeetools.ca/cgi-bin/picture?
&NETID=0345350502040532429&NTITEM=B1976

First off, would you guys recommend this machine to be a good
candidate for retrofit?

If so, I was wondering where I could obtain parts for a quality
retrofit? I am assuming I would need quite powerful motors, a
capable controller, and some ballscrews etc.

What size motors? I have been reading about oz/in and NEMA. It is
all quite confusing, but I am under the impression that with the
right hardware this can all be accomplished.

Is there a controller that is everyones favourite? A company that
has knowledgable staff?

I am assuming that the software to use is called Mach2 by artofcnc.ca
is that correct?

Thanks alot,
From Peter