We did Disney when the kids were 4 and 7; that was the perfect age range for the kids. Staying in the park was well worth it just to get into the park early and if you're willing to take them out of school...even better to avoid the crowds.

BUT, for the entire trip, the thing that we had the most fun doing was renting the little mini-boats on the Lagoon at The Polynesian. If we had just done that and only that, the trip would have been worth it!

Flying from Columbus or Indy to Orlando should be easy...

Cruises are better for older kids IMHO.