DHS is what you are referring to as MGM. DHS stands for Disney Hollywood Studios.

Remember that Animal Kingdom normally closes at 5:00 pm. But you could go to a nice restaurant outside of Disney after leaving since you'll have your car. Alternatively, you could try for a dinner reservation at one of the Disney resorts or at Downtown Disney after AK park closing.

I'd pick EPCOT over DHS because I love Soarin' (in the Land Pavillion) but there are no real roller coasters in EPCOT. However, Andi might be satisfied to get thrills at Test Track and Mission Space. Motion sickness warning: so many people got sick on the original Mission Space that they now have 2 versions of it. I also like the diversity of attractions in EPCOT.