There have been several Beaver owners who have had a white bed liner type coating applied to their roof with good success, but due to the extra labor and high expense, I only recommend this coating if you have a problem with a porous roof or one with slight cracking from hail damage. The Rustoleum Top Side paint will give you the slip resistance, and UV protection that you want at a much lower price point. After all, it is designed for painting the deck surface on fiberglass boats, and where else is slip resistance and UV protection more needed.
Gerald