Since I always recommend RideMax, I would use its software to help you decide ($20, but well worth it IMHO since it saves you at least 2 hours a day, for $3/day). The subscription is good for a year, so you can pick a similar date in September (they won't have the January data loaded until about November), and see if it shows you can do all the MK rides you want to do in 1 day, or all the AK rides you want to do in 1 day.
Offhand, I'd say MK 2 days and AK 1 day--even with Pandora.
Here's what we do. (you can do steps 1-5 now, for dates in September):
1. First, choose "which day/which park", based on the easywdw calendar. I'd check the RideMax calendar as well.
2. Select all the rides you want to do in each park (regardless of Fastpasses). Wikipedia and other sites have the rides for each park. YouTube is helpful for a preview if you're not familiar with certain rides.
3. Of the rides you want, "assign" your 3 FPs (for each park) based on
mesaboy's list.
4. In RideMax, select FP attractions (but not times) (Note that RideMax has tiering built in.) Also add in your dining reservations, and it will plan around those.
5. Then in RideMax, select the rides for each park. RideMax will generate the touring plans, including FP+ times. Ridemax will also tell you if you can't fit all your rides into your allotted times.
6. (for January, 30 or 60 days out) Then get on
MDE to select the FPs, based on the FP times in the RideMax schedule. (after you pick your 3 FPs for each park, you can usually modify the times)