Check Power Trader links on this forum, especially this post
from bettatail: there is a lot of information there and you can get some pricing ideas there also. Then PM bettatail and he will advise you on what's best for you. Quality people here.
I've done pressurized CO2 10 different ways from "mini' disposable cartridges, to beer regulators to industrial regulators: you learn a lot along the way, but in the end you will end up like the rest of us: with a CO2 tank, 2-stage regulator, solenoid valve, and a precision metering valve. Learn from my mistakes