Phil,
I got Mach3 a while ago..still learning.
Quite a while ago, I bought a milling machine (Bridgeport clone) and a 16x40 gear head lathe at an auction with the idea to eventually convert them to CNC...and to to build a CNC router from scratch.
Mach is quite powerful and fairly easy to use. Right now I have 2 PCs set up with Mach, one in the training mode for learning the program and the other one in the workshop with the real thing.
So far I scrounged together various bits and pieced for the mill conversion. I decided to go with steppers (as opposed to servos) for ease of implementation and cost), I found some new Pac Sci Nema 42 steppers, Hoffman enclosure on ebay and some surplus store, power supply from Antek, drivers from surplus, some parts from Duke surplus store, etc.
Other than the drivers, I plan to make my own PCBs for the breakout, opto isolator, distributor, power supply circuitry, etc.
Just send off an order to digikey and mouser for various electronic components. Still looking for ball srews for the table. A set from Rockford is about $850 with nuts... a bit steep. But I want to use ball screws to minimize/eliminate backlash. For the CNC router I plan to use rack and pinion for the x and y axis and ball screw slide for the z xis.
Anyway... back to Mach3. Other than the main site from Art Fennerty (machsupport.com), there is a group on yahoo and the cnczone.com has a subforum on mach. There is a guy in dowtown Durham that makes lamp shades buy turning logs into paper thin shades on huge industrial lathes. He converted old lathes to CNC control running them on mach3.
i'd be really interested what you are planning to dowith mach!
Cheers,
Bernhard