I recently saw a 2004 or 2005 34 PC fit with inboards that had an external stern thruster. The Boat was located @ Comstock's in Brick, NJ. Maybe they can take a picture of it for you.
That said, if the boat is fit with out-drives I doubt that any kind of stern thruster would work since they are generally installed mid-line i.e., in between the drives. When engaged, the thruster would be pushing water directly into one of the drives or the other.