Ok, is the plasma designed for CNC - if it is RF, scratch or contact start you will be in for a world of pain - been there done that.
The TB6560 does not have too many supporters i think, might be ok though, does it have a relay to control external stuff - this is what is used to fire the torch.
CNC Plasma is filthy dirty, if cutting stainless it can be poisonous too - ventilation is a must, you can build a water table which cuts just above a tray of water maybe 6" deep and stops a lot of the muck but then you have water in the shop and that leads to rust......
The mechanics is the same roughly as the cNC wood machine, does not need to be built as strongly as there are no cutting forces - its a non-contact process but does need to be rigid to get decent cuts.
You will need a torch height controller or THC - these range from basic to very expensive but is really needed to maintain any quality.
You will need an air compressor and dry air supply big enough to run the plasma.
I have built two tables and learnt a lot the hard way, in the end i bought a Hypertherm plasma system and have never looked back.
Suggest a look on a forum called PlasmaSpider - the Mach aspect of the system is a really minor point and simple to do, its the rest of it that takes the time and cash