I would make reservations for Be Our Guest now since they are always booked (the new ones always are), but I don't know about the menu I haven't been able to get in yet (I don't like to plan 6 months out).
I will suggest the Crystal Palace is a buffet and has Pooh Bear and friends, Chef Mickeys in the Contemporary is also a good choice. Sci-Fi diner and the 50's café at Hollywood studios are fun too. Did you want to be in the parks or can it be outside Disney?
Downtown Disney would be my first picks for choices of all ages. You have Rain Forest Café, T-Rex, Planet Hollywood and quite a few other places. We are local and our favorite is Rain Forest café and there is also one at Animal Kingdom. You can also check out the surrounding areas there are loads of fun themed places too.
I have eaten at many of the Disney restaurants and most will have children's meals so you should be able to find something they like, also remember that they may be too excited to eat. Our first time at Cinderella's Royal Table my daughter didn't eat anything, she was too busy with the characters (she was 3 then).