Nothing wrong with Mach if you like it and it does what you need.
For Mach I'd look at UC400ETH. It can run mach 3 or 4 using a plugin or uccnc which you could also have a look at to see if it fits the bill.
uc400 has 24 outputs & 10 in.
Those Acorn are expensive and the basic one only has 8 inputs & 8 out.