I don't know what a Quonset is, but the house I built has corrugated zincalume cladding on external walls and the roof. The walls are horizontal, no caulking is needed just start from bottom and overlap. There are some great extrusions available for both internal and external corners to which the sheets butt into making weather and vermin proof. I was told the horizontal sheets would collect dust, I have not found this to be the case. Horizontal sheets are best for a conventially framed house as they screw directly to the vertical studs. I built my house with a steel frame as well, all the outside is zincalume, not a scrap of paint, absolutely zero maintenance.
After spending a year building it, I bought another block to run more cattle, it just happened to have a house on it as well, I live there now and rent out my "dream home", but it is low maintenance.
Ken