CNC is not cheap.
You want to use Acorn? Buy AC servo drives that take step and direction. Putting stepper motors on that machine is an exercise in futility and going backwards in the machine's design.
Buy once, cry once.
If it were me first choice for that machine, All in One DC.
Second choice PERHAPS Oak and trying to reuse the old analog drives. I have not tried it, I'm unsure I would personally.
Third (and maybe my second) choice, is Acorn and GOOD AC Servo drives.
All these choices are going to put you between $2-$3k minium.
The resale value of the machine is affected as well in my opinion.
My .02
![Smile :)](./images/smilies/icon_e_smile.gif)
Marty