How would I make a fill station out of a normal paintball tank?

I play with a 22ci tank, which is usually enough to get me through at least two games of speedball.

But it's the third game that's kind of sketchy.

What I want to do is take a normal (like, a 90ci) tank and use it as a portable fill station so I don't have to walk all the way back to get air, and/or to top off if necessary.

I suppose the easiest thing to do would be to take the HP gauge off and run a hose from that to a manifold which has a gauge, on/off, and a bleed.

What's the cheapest way to do this? Your typical cheapie "scuba fill station" has almost all the right parts, except for the reliance on a scuba k-valve.


Any suggestions? On the cheap?