Currently there are 41 native Telephoto Prime lenses for Canon 70D and 33 of these lenses are autofocus (AF) type.
Canon 70D doesn't have a sensor based image stabilization system but 17 of these Telephoto Prime lenses features optical image stabilization.
Since Canon 70D has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 19 Telephoto Prime lenses with Weather Sealings.