Take your boys to Kennedy Space Center. It is an awesome experience. You will not be sorry. They may even have an excursion package for you.
One year we did Disney and the Space Center. To tell you the truth, we thought the Space Center was fantastic. We even got to see a rocket launch that day from Cocoa Beach. You may want to try to check the launch schedules. It wasn't a shuttle launch but still, none the less spectacular!
Have a great time with your boys!