exterior to be painted...

Okay, I am not going to use Aluminum on the exterior of my teardrop and want to paint it some combination of Crimson and Cream, or a deep red and a light cream color.
I don't have my plans handy, left them up at work, but what kind of wood or something, would I use on the roof that is bendable, durable for the weather, paintable and I'm making 5' wide so I would have to peice it somehow, right?
As always, cost is a factor....
thanks ===julie
I don't have my plans handy, left them up at work, but what kind of wood or something, would I use on the roof that is bendable, durable for the weather, paintable and I'm making 5' wide so I would have to peice it somehow, right?
As always, cost is a factor....
thanks ===julie