Currently there are 5 native Standard Prime lenses for Sigma SD1 Merrill and all of these lenses are autofocus (AF) type.
Sigma SD1 Merrill doesn't have a sensor based image stabilization system and none of these lenses have optical Image Stabilization.
Since Sigma SD1 Merrill has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 1 Standard Prime lenses with Weather Sealings.