Are you staying onsite? If so, will you be at a deluxe? If you answered those questions in the affirmative and your visit is on a Monday, you'd likely be entitled to extended evening hours at EPCOT, which would help you with your evening touring and hopefully give you time for a nap back at your hotel in the afternoon.
If you can arrive early at AK and work out good touring plans for both parks, Genie+/ILL shouldn't be needed, although you might consider it if you're visiting during the first week of January, when crowds will be a couple of ticks higher (from people staying on after Christmas and New Years) than they will the rest of the month.
Regardless, several authorized resellers, and WDW, sell 1-day parkhoppers -- and strangely enough, for those particular tickets, the WDW website is sometimes the cheapest option. Compare prices for them for your intended date (with tax and fees included, so it's an apples-to-apples comparison) here: