Two of our favorite resorts! We are also going in Oct (4-13) and staying at AKL.
We stayed at AKL for our 1st visit to WDW and thought it was a perfect 1st resort. The theme is amazing, beautiful rooms and lobby. Bus service is excellent and great food options. Feels like you are on an African safari and it's very quiet.
The Poly is our favorite. Huge rooms, awesome location and day bed in every room. Feels like your in the middle of everything. Watching Wishes from the beach/pool or GCH is heaven!
With kids that age, both resorts are appealing. If you want a little more space in your room, go for the Poly. The day beds are comfy and a great option. AKL has bunkbeds, if your kids don't like to sleep together. The Poly is very convenient to MK and EPCOT and the bus service was great for us.
Either way, they are great resorts