Sorry didn't see the reply, had a busy weekend.

I'm also using an Acorn on my Shiz. Very nice to use and great support on the forum which is well supported by Centroid and users. Not deadly cheap when you pay for the full licence and MPG but it's a good, semi professional system. https://centroidcncforum.com/viewforum.php?f=60

The SEM machines on my machine had both encoders and tachos but you don't need tachos with modern drives. The original encoders connected up directly, as they had differential outputs. Check your motors to see what you have in there before buying anything extra. You might get lucky like me.

For the DC power I just got a 3000VA 120V site transformer from Screwfix (the ones in the steel box, not the potted yellow things) and removed some secondary turns to get 100VAC, then used a bridge rectifier and large electrolytic from CPC. Gives ~140Vdc and is simple, cheap and reliable. 160-180Vdc would be too high.

I have a Newker 990MDCa standalone 4 axis controller on my Bridgeport conversion. Works well but the manual was impossible to understand and I ended up writing my own. Depends how patient you are. Dean / Jazz is going with SZGH, who sound like a much better bet.

So my Shiz just required an Acorn and 3 of the cncdrive drivers, no mechanical buggerage needed. Pretty quick and simple although modern electronics is considerably more compact than the original stuff, so I made up a new cabinet while I was at it. The old one was big enough to climb inside. And I rebuilt the head, replaced the bearings etc, as you do.