you can get a brass one at home depot or home hardware.
you can use in in the maf with some non conductive paste so they dont corrode each other.
if you find an aluminum on let me know
stainless or ally huh… not going to happen in Canada… look at some of the online US mail order places… a NPT barb fitting in either of those materials is WAY outside normal spec. you’ve better off welding on an AN fitting …
whats wrong with drilling / tappinga nd using brass? you could even braze it on if you’re scared. Also there are vaccum lines that are in the intake manifold that you could tee that are after the throttle body