I assume you have already taken a look at my guide to pressurized CO2.
Yeah I did weeks ago. Completely forgot I read it and that I had a thread about building a CO2 Regulator.
I am not sure what you mean by "other commercial brand" as Victor is just a particular brand (there are many others).
I meant the cheaply priced regulators where you can get a dual guage regulator with solenoid value for $100-$170.
As for the solenoid valve, you can purchase these separately as well. Just make sure that the fittings that it uses matches the European Standard (BSPP, most likely).
They use BS standard connections here. Can't find a solenoid valve here of metering needle here will probably order online. Any recommendations? Solenoid dependable one. Metering needle to improve the accuracy of the C mode.