Hi there Jamie!
How exciting to be visiting the Walt Disney World Resort in just a few weeks! I think you are very wise to devote a full day to experience all that Magic Kingdom Park has to offer.
When choosing a park for your arrival day, I would check the
park hours and plan accordingly. I would not suggest choosing a park that will close early on that particular evening. If Disney's Hollywood Studios will remain open later on that day, I recommend it for your thrill seekers. Be sure to book
FastPass+ selections in advance in order to decrease your wait time. My suggestions for Disney's Hollywood Studios include: Rock 'n' Roller Coaster Starring Aerosmith, Star Tours - The Adventures Continue and The Twilight Zone Tower of Terror.
For your second full day, you may want to consider spending your morning at Disney's Animal Kingdom Park and your afternoon and evening at Epcot if you will have the Park Hopper Option on your tickets. If you have base tickets, I suggest visiting Epcot while making sure to experience Soarin', Test Track, Mission: SPACE, Spaceship Earth and Frozen Ever After.
I hope this information is helpful to you. Please don't hesitate to stop by again with any additional questions that you may have. Best wishes for a magical trip, Jamie!
Happy Planning,
Jodie