Your local industrial-supply catalog will have lots and lots of solenoid valves. What country are you in?
10-20psi is very low pressure. Many of the valves will have a minimum pressure higher than this. (They use the air pressure to do most of the work of opening the valve.) Make sure you check the specifications closely.
Most industrial solenoid valves are intended to run off industrial voltages. You can't send 5v out into a process plant and expect it to come out the other end of a wire 100m long. They use 10v or 24v very commonly. You will probably need a relay or a MOSFET driver to interface to the solenoid valve.