For a video/photagraphy platform vibration needs to be minimized. It makes the video hard to watch and still photagraphy blurry. So an electric power system would be best. However, I cant stand the expense involved in electric and can justify batteries for a plane that size. So I would go with the Zenoah G-26 and work very hard at mounting the engine with shock absorbsion in mind (Rubber isolation mounts) to reduce vibrations through the airframe.