If you already reserved your room through AAA then all you have to do is call them back and tell them what tickets you want to add and add the dining. The only discount you can get currently is on the room portion from AAA, but they will be happy to let you keep your room discount and add the package features you want.
The tickets you buy from them will be the same tickets and prices you would get from Disney.... so might as well order them through AAA and then you can get the dining package if you want it.