Currently there are 1 native Standard Prime lenses for Pentax 645D and all of these lenses are autofocus (AF) type.
Pentax 645D doesn't have a sensor based image stabilization system and none of these lenses have optical Image Stabilization.
Since Pentax 645D has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 1 Standard Prime lenses with Weather Sealings.