Oh, how I love planning, whether it's my trip or someone else's! Anyway, here are my thoughts, and a few "fav" places to eat. Lets' do the food first, because it's nearly lunchtime!
OK, my "Can't Miss Meal Stop" is always, at least once, sometimes as many as three times a trip, Prime Time 50's Diner. It's fun, the food is fantastic, the atmosphere and theming is spot-on. Just love it. Another MGM spot that's fun, although the food's not nearly as good, is the Sci-Fi Drive-In. But if ou have kids who might need help eating, this might not be such a great place, as the way you're seated isn't traditional (as in you face them), but as if you're in the front seat of a car, they're in the back (or vice-versa). Could make things dicey.
Animal Kingdom wise, I love Flame Tree Bar-B-Que and Tusker House (chicken... yummy).
Magic Kingdom... I don't know that I've ever done a sit-down meal there. I know I really didn't like Pecos Bill (dry burgers... blah), although many people have defended it against my rants in the past.
Epcot: I'm a big fan of the Rose & Crown, or even the fish & chips shop right next to it (big bonus to the take-out fish & chips: You can take it over to the park across the street and down the lane from the Rose & Crown and eat while the kids play). Also love Marakesh, although it might prove to be too "adventurous" for tots.
As for taking a monorail to a resort for a meal, I've done that, but since I don't have kids, it's a whole lot easier. Might be tough convincing kids to leave the park, even for a while, with the promise of a meal. Might also prove a bit time-consuming if you're on a limited-time kinda trip, which it sounds as if you are.
park wise, I'm betting the kids will LOVE Animal Kingdom. I mean, what kids don't love animals? And of course, they'll want to stay forever in The Magic Kingdom. Epcot might prove a bit more challenging as far as keeping them entertained, but if you do a little research, you'll find all kinds of cool things for them to do!
Have a great, great, trip!
Richard