LOL, having seen what it does now, I would never want to mix plasma with any sort of other machine

Two totally different beasts here - plasma needs massive acceleration and speeds unto around 9000mm/min (45A system) and machining needs more rigidity at the expense of speed and acceleration.
Cutting figures -
3mm single flute tool,
5000 series aluminium,
1mm depth of cut,
Pocket milling ( a hard task),
10,000 rpm,
323mm/min cut speed - way lower than plasma
Cutting force - 8Nm - plasma would be zero (unless you like torch diving

)
So there is no comparison really apart from both being CNC.
Drip pan is a good idea to allow for some sort of coolant, spoil board can be simply mounted on whatever rigid bed is used.