Well I have to disagree and NOT recommend the Animal Kingdom breakfast at Restaurantasaurus. I told my story on another post about character breakfasts, so I won't go on again here, but suffice it to say :IT SUCKS! Avoid it at all costs!
Secondly, I'd say Chef Mickey's is great, as is O'hana's at the Polynesian. Hollywood and Vine and the Studios is great as well!
Seating. Well, let me ask you this: Are you all going to be paying with one check? A party of 18 with seperate checks is going to be a nightmare for the poor server. How about you let the CM know the individual parties and get seperate PSings. Then when you get there just all check in together and let the CM know you would like seperate tables near each other. They very often have whole sections empty in the early part of the morning (say before 8) and should have no problem accomodating you.