Durable paint formula, highly resistant to infrared in the sunlight & extreme climatic temperatures

I have an old country home in the Himalaya's which has a corrugated tin sheet roof. The altitude of my home is 10,200 ft above sea level. As is normal at this altitude, the ultraviolet levels in direct sunshine are very high during the year. This is further compounded by the fact that the variances in temperature during the year are extreme & the roof has to also take the battering of heavy snowfall in the winters & dry heat (tin temp about 40 °C at the max). Needless to say, that the use of all standard paint products have failed to give a life of more than three years. Luckily, I am married to a paint manufacturers daughter, so my question is does anyone have a formula of a paint that gives the longest life as a roof coating under the above circumstances, it would be a one of batch that I would custom order for my self.

Thank you.

Better try automobile paints because they are highly resistant to UV rays & they are compatible with aluminum surface.