We did Princess Storybook for dinner. My boys didn't hate it (they're certainly older than yours), and the atmosphere is nice. We met Jasmine, Aurora, Belle, Ariel, and Alice. Jasmine was very funny and teased by boys, and Aurora gave my DD a nice kiss on the cheek.
Remember that you are not guaranteed any princesses at the meal, so you can't rely on seeing a particular lady anywhere.
If you just want your little guy to meet some, you could also try the various countries in World Showcase. We saw Aurora and Belle in France, Jasmine in Morocco, Alice in England, and Snow White in Germany--all with very little or no wait. Alice, for instance was sitting down coloring at the Kidcot station in England. DD4 sat next to her and designed her mask. So there's not a real need to do an entire meal, especially with a little guy like yours, who depending on the day, might not be in the mood for such.
Have fun!