Currently there are 5 native Telephoto Prime lenses for Olympus E-1 and 2 of these lenses are autofocus (AF) type.
Olympus E-1 doesn't have a sensor based image stabilization system and none of these lenses have optical Image Stabilization.
Since Olympus E-1 has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 2 Telephoto Prime lenses with Weather Sealings.