Since it is an Illuminations Cruise, I'd suggest dining in the Epcot Resort (YC/BC/BW/S/D) area, just to be that much closer to your departure point. And, I'd say choose a restaurant that accepts ADR's, and book one, so you can be more certain of eating 'on time'. Can't suggest any particular place over another based just on the age groups, but there are several excellent restaurants in that area, and a good variety of menus to boot.
Note: I would say cross off your list Beaches & Cream at the Beach Club. They do not take ADR's, and a party of that size will be difficult to seat together, in such a small location.
Maybe others on the board can help with a selection....