call Disney Dining 407-wdw-dine.
Make them like any other dinner reservations. "I'd like a table for four at Ohanas for 8am on September 7th."
As to preference - I think that depends on you. Do you have a preference for Pooh or Princesses (I'd guess not). How about Stitch (only at Ohana). Tradiational characters? Is life incomplete without Mickey? How about Donald or Minnie? Do you like buffets or family style or preplated? Do you want to do this on a park day, or are you interested in doing it at a resort? Breakfast has more options than dinner, but some people really want dinner. Is there a resort with a character breakfast you are dying to peek inside?
Our traditional breakfast has always been the Poly...used to be Minnie and it was a buffet. Then it was Mickey, Pluto, Goofy and Chip and Dale and served family style. Now its Lilo Stitch Mickey and Goofy and served family style. We like it because I'm not a buffet fan - because I am a Polyneisian resort fan (I just like to visit the place once a trip), and because with an early reservation we can get out just as the MK opens - which makes it very time efficient for us. Now with an eight year old boy, Stitch is a draw in and of himself.
Other people have a tradition of Chef Mickey's on the first night. Donald's Breakfastasaurus often gets mentioned as a good "boy" meal. Grand Floridian has reportedly the best food (haven't eaten there in years, but years ago it was good), but its characters tend to be the more "Victorian" - Alice and Mary Poppins. Beach Club tends to be easy to book. Garden Grill has good character interaction - no breakfast, but the rare lunch and dinner offerings. Crystal Palace has Pooh and friends.......etc.......
