With 4 days I think you want to not plan around the one ride. the parade at HS is perfect for boys. Toy Story and Star Wars!!!!
Buzz Light Year in MK will be just as fun. The kids are going to Love AK. Also Epcot. Testrack if they are tall enough and Soarin.
You will have a great time even if you do not make the TSM ride...
HS is a perfect choice for late arrival. That or Walking the countries in Epcot.
Is the area open by Star Tours where the kids could pretend to be stomped on by the imperial walker? Is so the picture you can take there are awesome. Also pics with a fake R2D2. Amazing...