Well should you edice to get DP your son is free. So it would be the 2 of you. you would get a counter service, a snack and a tableservice. It goes by nights staying. so you would have 2 of each. I usually split the counter or table. One the first day and one for the last day. Usually works out if you plan right.
Not sure which parks you plan on visiting
some table ideas:
MGM - 50's Prime Time , Sci-Fi and Mamma Melrose is ok
MK - Tony's, Plaza and Liberty Tree isn't bad, Crystal Palace is good & you said you got it perfect
Epcot - The Land has favorite CS and the land has a nice all you can eat meal (depending on your fa,ilys food likes)
the resorts have great meals also
GF - 1500 Park Fare (buffet) Cinderella, Prince Charming hard to get in but you never know if someone cancels
Poly - Kona Cafe
Contemp - Concoarse steakhouse, Cali grill, chef mickeys (not one of my fav though gils liked it)
Wilderness Lodge - Whispering Canyon
remember almost anywhere you go there is a decent kids meal...they are trying to be much healthier than they have in the past.
You can always call dining reservations, they will help you find reservations. Usually pretty good. They can tell you what they have avail on computer screen. Not to mention you can call everyday to see if there were any cancellations. if you check out
www.wdwig.com you can pull up all the menus. If you have questions about specific ones post it here someone will help out. Good luck.