The make your own sundae from the Coral reef is the reason my kids beg to go there every trip. And not on your list but I will second the above poster the new favorite is the Kiddie Cone at Kona!! That is enough for 2 easily and they LOVED it. The fancy cinderella slipper is gorgeous but my dd(8) wouldn't eat it. She thought it tasted yucky(and it had fruit on it! Heaven forbid there is fruit in her dessert!)
Definitely have to agree with Java - kiddie kone is rate the best by my kids, and although the slipper and dog bones were cute the kids actually liked the desserts at 1900 Park Fare better than night - go figure. We stayed at the GF last summer and had the mini wedding cakes delivered to our room (you can get them at their restaurants also) and they were really good. We're trying Coral Reef this summer so we'll see how they like them. I do miss the pineapple with the caramel sauce at Ohana.