Hi Terry, If it is a fantastic pool you are looking for, then Disney's Yacht and Beach Club is for you. This is our favorite Deluxe resort, as it features "Stormalong Bay". As described on Disney World's website, "Stormalong Bay spans 3 acres, with water slides emerging from the life-size replica of a wrecked ship, lagoons, a slow river to float along in inner tubes and a sand-bottom pool." It's like having a water park at your Resort! While your 6 year old would enjoy the slide, waterfalls, whirling waters and lazy river...your baby will likely have a ball in the sandy beach/shallow pool area.
The Yacht and Beach Club is in a phenomenal location, because it is walking distance to Epcot and a quick boat ride to Disney's Hollywood Studios. Here are two links to the this Resort. The Yacht Club is HERE and the Beach Club is: HERE . These 2 resorts meet in the middle and share the Stormalong Bay.
If you would prefer a Moderate level Resort, you may enjoy Disney's Caribbean Beach Resort. The pool is described on Disney's website as, "a sprawling pool complex themed like an old Spanish fortress—complete with towers, antique cannons and a waterslide.". As an added bonus, there are Pirate Ship Themed Rooms available that your son may find exciting. These rooms do cost a little extra and need to be requested at reservation time. This is a link to this Resort: HERE
Hope this helps. Thanks for visiting the Moms Panel and be sure to stop back by with any other questions you may have.
Kaylene