> perhaps 316 stainless steel

Stainless steel is awesome! Unfortunately the connections are not so easy. Stainless steel-to-brass threaded connections are probably safe under most circumstances but are dubious per the code. Push-to-connect fittings often use little stainless teeth to hold the tubing in, and this may work less well when the pipe is nearly as hard as the teeth. (John Guest makes special fittings for stainless steel tubing.) You can’t sweat stainless steel pipes.

Obviously everyone should plumb their houses with swagelok fittings! :)