I took a look at a couple of local shop yesterday. Now I'm leaning towards replacement head rests with the systems built in. One shop has a Vizualogic system pre install for a killer price. The video quality on the Vizualogic was better than any other one's I looked at. Plus this gives me the ability to have two different videos playing or both playing off one source. That's be cool for the wife and little one to chill in the back for road trips. The aftermarket roof mounted deals seems clunky once I held a couple up in the car. They are so thick and I don't care about the build in dome light. I'm not sure there why there is not a product out there with a super slim mount screen and remote source. Kinda like an iPad sized screen (even twice the thickness would be great) that would be clean. There are roof mounted monitor options that require a separate source, but the monitors are still super thick.
Of course now I'm thinking why not a 20" monitor, new head unit, amps, speakers and an XBOX install would be cool... Not sure when I'd ever actually sit in the car to play XBOX, but it would be a cool set up. Since you can fold the front seats down to create a bed/lounge chair set up with the rear seats, gaming in there would work for sure.