Hey Z, if you wind up going to Disney, I can't recommend enough the fireworks cruise. They have one both in Epcot and the Magic Kingdom lake, but I'd definately go to the Magic Kingdom lake one because the epcot one you're VERY close to the fireworks and it's insanely loud and you get ash raining down on you

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Last time I went it was about $160 USD for a pontoon boat that picks you up at any of the resorts on the lake (Polynesian, Grand Floridian, Wilderness Lodge, Fort Wilderness), and you have a driver. The boat is stocked with drinks, chips, etc... and a boat driver... they take you around the lake and show you the sights & tell tales, then take you over to the electrical water pageant and let you watch that, then they float in front of the magic kingdom, turn on the speakers so the same music in the parks is piped into the boats, and you watch the fireworks from the water, which is amazing... the booms REALLY carry over water.
With your family breakdown, you might love the cabins at Fort Wilderness... tons of stuff to do there as well as having peace and quiet.
And another big thing about the resorts is the restaurants! With kids some of the best would be the buffet dinner at O'Hana's in the Polynesian resort, the Crystal Palace in Magic Kingdom... and DEFINATELY check out the Hoop-De-Doo Revue in Fort Wilderness.
You can read and see picture about all these things at
www.allears.net, including reviews from other people staying there.
Steve.