Start asking why manufacturing companies have drug their asses fixing the obvious issues plauging the security of our cars. Basic thingslikee having physical keys that function like a key. Not a RFID tag. Push button start is so fucking lazy for security.
Even galvanized will rust together. I like brass valves but PVC everything else though i like the black plastic non potable line but make sure you rigid Mount everything. Drive a fence Post or rebar or… and tie the plumbing to it as close to the valve as you can to keep it from flexing as much as you can. This will give it the most longevity vs anything else including material choice.