or just any high heat/bio exposed areas?
Believe it or not, one of the safest places to be when lightning strikes is a car or other motor vehicle, because the rubber tires, being non-conductive, tend to act as a repellant against the electrical discharge.
Aluminum will be fine. You do want your girth to have elastic and roller. However, a neoprene girth would be easier to keep clean. all you need is to wipe it down with a wet rag. A cotton one will absorb sweat and is less sanitary especially if it were to ever be used on more than one horse. With stirrup leathers, all that really matters is strength.
You have to put them in if you sell the house.
