Sorry I missed your message till now.. Not a big forum user and did not receive an email..
Anyways, needle valve I am using is right from home depot. Watts a-41.
Parts I am using...
20oz CO2 tank bought at BadLands Paint Ball in Pickering
ASA On/Off Bought at premium paintball products across road from badlands
1000PSI gauge - also at Premium Paintball
Watts A-41 Needle valve at home depot
CO2 Hosing -Home depot as well
Then you just need bubble counter and a diffuser or reactor..
You growing plants already, what kinda tank? I have 2 of these paintball solutions running now. One on a 20G Tall and a 5G. Still learning and some crap plants but starting to look for more interesting stuff other then Big Als stuff.