Are you staying onsite or offsite?
For your age ranges, I'd recommend one character meal. Chef Mickey is a classic and a lot of fun for your age range of children. It is a bit of a splurge at $30/adult for dinner, but it will be a good experience.
We too like to treat ourselves, but not overdo it on costs. Try to mix it up. One character meal (those are usually the most pricey), maybe one fun place like Planet Hollywood, Rainforest Cafe, or T-Rex, and the rest of the time you can dine at Family Friendly Restaurants like Bahama Breeze (fun, casual atmosphere) located in Crossroads Shopping Center, Chevy's Tex-Mex, or an off-site Japanese Hibachi.
Have a great time. Go into the Budget Boards too as there are a lot of discount and cheap eat ideas.