Hi Vanessa,
You are in for a treat when you visit all four parks and the water parks!
Since you do not say how many days you will be at the Walt Disney World Resort, you currently are looking at purchasing a four day
ticket with the Water Parks Fun & More option. This will allow you to spend one day in each of the major parks and then two days in the water parks.
However, when I am planning to tour all four parks, I generally allow at least a day and a half each for Magic Kingdom and Epcot and a day each for the Disney's Hollywood Studios and Disney's Animal Kingdom. This allows my family to not be up at park opening and stay until park closing. Otherwise, we are too exhausted.
If you only have six days in total at Walt Disney World, I would make sure to take break at a water park after Epcot as this is really two parks in one. There is a lot of walking at Epcot (
Every
Person
Comes
Out
Tired) and you can sleep in after this park and visit the water parks later in the morning the next day.
Wishing you a magical vacation!
Beth