Currently there are 28 native Wideangle Prime lenses for Panasonic G9 and 15 of these lenses are autofocus (AF) type.
G9 also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on G9.
Since Panasonic G9 has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 4 Wideangle Prime lenses with Weather Sealings.