Hi fairytinkerbell! For dinner, both 'Ohana and LTT would be great choices. If you'd like a character meal, LTT would be the choice to make. Plus, you wouldn't have to leave MK to eat. If you want to see the MK evening parade and fireworks, you could plan your LTT dining time so that you could line up to watch the parade after dinner.
'Ohana would be a lot of fun too. You can just hop on the monorail from MK and be there quickly. They have fun games for the kids, and you could stay and watch the MK fireworks from the Polynesian beach after dinner if you wanted.
For lunch, we usually just grab counter service food if we're planning a big meal for dinner that evening. Both 'Ohana and LTT are pretty big meals, so you may want to just a have quick bite from counter service for lunch. Some good counter service choices at MK are Peco Bill's, Cosmic Ray's or Columbia Harbour House.
As far as food, jcemom has given you an excellent link to the WDW menus.
Happy planning!