Hey Alex,
First, :sign0016:to the site.
Sounds like you've got a good truck on your hands. There are a lot of manufacturers that make cargo units and what not for the burban, so you should be able to find something pretty close to what you want/need.
Some people here have gone with a headrest for their video/dvd system, and they like it becuase it's portable and can be removed and taken to another vehicle...also gives you multiple screen options sometimes as well. I reviewed the Yukon XL Denail that cames with the media system and that had one center video screen that seemed to be pretty comfortable for the 2nd and 3rd rows to see as well. It's always an option to have it roof mounted, but that's a bigger project.
Not sure about the brakes/rotors. I've never gone with the high performance ones, but I hear that they can offer better performance, expecially if you're going to be loaded up or tow anything.