If you are definitely going to the water parks, consider the Park Hopper +, but if you are not interested in the water parks, you might want to consider the regular Park Hopper 5 day pass. Remember, the park hopper + only gives you 2 entries into the water park, not unlimited.
My suggestion would be to buy the regular 5 day Park Hopper and then buy individual passes to the water parks, but that is only my suggestion.