Here's a bunch of Maya Riviera all-inclusive resorts:
http://www.cancunallinclusive.com/resorts_rivier_maya.htm
My wife and I had our honeymoon in the Yucatan (Cancun, Cozamel, Playa del Carmen, Quintana Roo, etc). We had a beachside bungalo, however. Great time!
Hanalei bay Kauai is in Hawaii. Maybe you might consider picking an island in Hawaii, and take your search in that direction. I'm sure Maui would provide no shortage for you and your family. You can certainly put together something on your own in your budget. There's a lot of travel resources available. That's not to say you won't find an all-inclusive in your range, as well. Good luck.