Hi,
I like the Ethernet SmoothStepper (ESS) by Warp9. Its not the only choice but it is a good one amongst other good ones!
It will give you up to six co-ordinated axes....enough?
One, or if you want some more inputs, two BoBs, the old parallel port types plugged into the ESS and your set to go.
They can pulse at 4Mhz, 160 times faster than a parallel port and it allows you to use a late model PC like the LattePanda
I linked to.
I think the Mitutoyo scales and counter unit can be run as a separate system. A little bit of electronic trickery might be
required to get the scale to talk to Mach but is possible.
I personally think Mach4 is appropriate for new projects. Mach3 afficionados will disagree (i used to be one myself) but its so much
more flexible and stable.