Galvanized steel want to buy Greece

I am writing to you with an inquiry about the galvanized steel purchase. I am located in Athens, but the production is happening in the USA (East Coast). We need to use it for prefab houses construction. We are interested in a wholesale purchase and long-time partnership. Would it be possible to ship it to the USA East Coast ports?

What thickness of galvanized steel sheet/roll would you recommend for a prefab house construction for all year round living ? Tell us please the price per 10 kg of galvanized steel.