I've used the standard hardware store soft 1/2 inch aluminum tubing on many race cars with no problems , I do secure it so it won't vibrate or rub and try to stay away from the headers and exhaust system
As you know being west of the Rockies helps on the corrosion problems the wet states have east of the Rockies
I did replace the S.S covered rubber core tranny cooler lines two years ago with new Viton lined SS lines as preventive maintenance do to not knowing how old they where, when in doubt change it out