The only thing I would add to the discussion is that when you get around to buying
the Stainless parts
to make another, I would use butt welded fittings, a screwed fitting has the thickness of the metal reduced by the threading. Get the fabricator to 'pickle' the welds ie. paint
them with acid to remove the slag and stop any rust forming.
Either 304 or 316 grade Stainless are acceptable, personally I recommend and only use 316.