I just thought of a product that we use in the commercial Refrigeration industry!
Theese are selonoid activated valve bodys that are desined for high psi's, freon, water psi, ect! We operate our valves at PSI's of up to 500 psi everyday!
Check out this site http://www.sporlan.com/Prodinfo.shtm
The coil part # MK1VDC 12v dc, and there are a number of valve bodys you can choose from. [ 3/8 flare, or 3/8 odf sweat, ect. ]
I think you would want a valve body made of brass anyway.
You would have to buy through a Dist. heres one www.uri.com
than you will locate a nearby branch!
Hope you find what you are looking for!