Media Directors have On Screen Orbiters, but the Orbiter is separate from the Media Director. Think of the Orbiter as a remote control for the Media Director. The On Screen Orbiter isn't really remote, but it allows you to control it with various standard devices like keyboard/mouse, gyration mouse/remote, etc. You can also have the Orbiter completely standalone and put on a mobile device to control any media director in the house. Using the Nokia 770 for this seems to be increasingly popular.
I forgot to answer your original question... No, you do not need any special video card in the core... or any other media director for that matter. You only need such video cards if you intend to use UI2 (alpha-blending and such) on the device that the video card is using. In your case, it doesn't seem you want to use the Core as a media director at all, so a cheap video card would suffice.