Yes, wind guards are absolutely necessary. As per ASCE 7-98 code to make your building safe from wind the wind guards are needful. The main purpose of this guard is to keep the metal roof safe from hurricanes, winds and most people say tornadoes. Wind guards provide extra strong support for the roof to the purlins. To make choosing beautiful you can get them color matching to your roof. To make the metal roofs long lasting you need to focus on durability over other extra features. So, without picking other features, prioritize the better durability for roofing.