Hi Andrea!
I would definitely try Chef Mickey's! Chef Mickey's is located in the Contemporary Resort, which is literally right across the street from Magic Kingdom. You can just catch the monorail from Magic Kingdom to Contemporary, which should only take a few minutes.
Chef Mickey's is a favorite of a number of guests! My family has eaten there both for breakfast and dinner, and really enjoyed the food and overall experience.
Not only do you get to see the "Fab Five" of Mickey, Minnie, Donald, Goofy, and Pluto, but you'll also see the monorail coming and going at the Contemporary, which was cool. Right outside the check-in area is a nice lounge area where kids and parents can sit (TV there also), and made for a nice detour if your child needs a little "break" from the action :-)
The service has always been good, and there seems to be decent table space there between you and neighbors, compared to other character dinings, when areas can get cramped when the characters come out.
I would do no more than 2 character dinings a day, however. So if you do Crystal Palace (breakfast, lunch, or dinner) or Chef Mickey's (breakfast, dinner) make sure one of the meals (lunch maybe?) is not a character meal. It's great seeing them, but you'll find yourself wanting that one meal with no characters around...
Good Luck on all your Disney planning!