It might be an obvious idea with him coming from paintball.
But going from paintball HPA to airsoft HPA comes the issue of output pressures. A typical paintball cylinder outputs somewhere around 600psi (But could be unto 850psi which was the original paintball output to align with the CO2 it replaced)
Mechanical paintball guns tend to work with that high pressure, electronic ones have inline regulators bringing it down to about 200psi.
Going to airsoft HPA still brings the need of the more expensive parts of the airsoft transposition.
Its also likely that he has full size paintball cylinders, so for the convenience if going to HPA @Ryfoolz may need to buy a 13ci cylinder*. He's shown an interest in SMGs and CQB, so putting on anything but a 13ci in a stock means added bulk and a remote line to tangle up.
*Not everyone has about 5 or 6 cylinders of different shapes sizes & weights in the cupboard like me, not counting my out of date collection!
