I think you should contact some good Construction Companies in USA & Some of them are:I need to rebuild arched openings with square. I was thinking about cedar or treated but they have pros and cons.
Currently it's for under a cantilever and they are fine except ground contact. I'm thinking if they were primed before installed they would have survived fine. So given the age of the customer and all of this I don't think I should reinvent the wheel.
What say you?