I would forget places like zapp automation. The u.k. has some junk available.
If I did my mill again I would:
1. Go closed loop.
2. I'd get AC powered drivers 20-80vac like:
https://www.ebay.co.uk/itm/EU-Ship-W...-/223484030824
3. Get 2 toroidal 35vac supplies wired in series for 70vac (7.14A) and wire them direct to 2 drivers each for 4 axis. These would leave headroom as the idle voltage would be above 80v. like:
https://uk.rs-online.com/web/p/toroi...ormers/1233994