Hi Tweakie,
I'd guess any drivers would work, I was referring to the CPO-10V BoB. (maybe a typo ?)
As far as squaring, I'd seen it mentioned where after homing the (stepper) axis, one can usually turn one motor one click at a time by hand to true it up.
Or, square it up before power up and it is usually fine enough.
The OP Steve mentioned 2 separate X,Y tables in sync., so squaring might not be an issue.