Hello Suresh,
Thanks for stopping by. I just returned from a week-long vacation at Walt Disney World, and my two water-loving boys and I included visits to both
Typhoon Lagoon and
Blizzard Beach. In fact, whenever we visit for more than just a few days, we visit both water parks. From my perspective, if your kids love water attractions, this is a great option, particularly if you are traveling during the warmer months, when the theme parks tend to get very warm by the middle of the afternoon. It is hard to be hot when you are soaking wet! As for your children's different swimming abilities, you will find attractions that are appropriate for all ages and propensity for adventure at both parks. In fact, both parks have a great mix of "mild" and "wild" attractions. Both have several raft rides and slides, as well as lazy rivers and giant pools, offering a wonderful array of choices to keep your entire clan happy. In addition, complimentary life vests are available for your younger son in the event that this would make you more comfortable.
I hope you have a magical visit splashing around!