Hi there Crystal!
Thank you so much for your question! September is a great month to go to Walt Disney World! I've been several times during the month and the weather can be a little better than the middle of summer.
In my opinion, adding the Park Hopper option to the
Standard Walt Disney World Park Tickets is the best way to get the most out of your trip! While one park may close early like Disney's Animal Kingdom; Magic Kingdom, Epcot or Disney's Hollywood Studios may stay open longer, letting you park hop from one to another.
The moderate resorts are a great place to stay for both you and your kids. I really like the feel of
Disney's Caribbean Beach Resort and I have heard lots of good things about
Disney's Port Orleans Resort - Riverside; another option could also be
Disney's Art of Animation Resort. The resort is brand new and caters perfectly to your kid's age group.
I hope this gives you a starting point for your vacation! Please let me know if you have anymore questions! The Moms Panel is always here to help! Have a Magical Day!