Aluminium CNC log.

[Jonathan]

I'm ordering a cheap mouse and a Serial cable today.

Mice are handy, but what's the serial cable for? Did you mean parallel?

what sort of cables do I need for hooking up the breakout board, PSU and Drivers etc?

For the PSU to driver you'll want something that'll conduct the required current without a big voltage drop. Probably 1.5mm^2. Some people use shielded...I don't think it's required in most cases.
For the breakout board to drivers standard 7/0.2 wire is fine (or anything you have lying around) as it's only a signal.
Drivers to steppers generally CY 4-core (which is shielded), 1.5mm^2. You need minimum 1mm^2 from the VFD to spindle, so the same as you use for the steppers will be fine.