I am 3rd generation roofer and also a master plumber and the BEST material for roofing should be installed by a plumber or qualified tinsmith
The best roof I installed 45 years ago is going to last another 200 years at least
All I used for the roofing material was lead coated 14 ounce copper with soldered seams.
At that time I charged $100 per Sq foot
So your saying "Beat materials" and green well considering the lead and copper were recycled and should have a life expediency of 200 - 400 years and then these materials can be used again
The reason I opted for lead coasted copper was to protect the copper from possible bird droppings and acid rain.
Lead is great for being acid proof and copper have over 6,000 years of proven reliability
The picture included is a 5" lead pipe I removed from a building that is almost 200 years old in Manhattan and the only reason I replaced this pipe is the new roof called for cast iron drains with caulked lead joints. They should last about 100 years as I used 4 PSF sheet lead for the flashing material 3'x 3'