For the PM 6 the air system you want is a 4500 psi fibre wrapped tank, and for the best results you want a hp (high pressure) reg, the PM will work on a lp (low pressure) reg but you will need one with a very fast recharge rate.
The size of the tank eg. 1.1 or 0.8 will depend on the position you play, what you are playing (x-ball, 7man, woods ball etc.) and also personal preference.
Hope this helps
Matt