DON'T get the overhead console version. You will have zero visibility from the inside rear view mirror. Headrest monitors are the way to go. Look at Crutchfield.com to see what they offer.
To answer the OP yes, it can be done. The above is a true statement however I never use my rear view mirror anyway, the tint is way too dark combined with the cage make it hard to see very well but the screen location will be a case by case basis.
The only issue with the headrest monitors are their size or lack there of. You also want to make sure you have an HDMI input. While you may say the DVD is great my kids would much rather play Xbox or watch satellite TV on a long trip. Both our QX and Expedition have rear monitors, our QX has a nice 24" HD center mounted and the kids love moves and games on that. My expedition has the headrests and they ALWAYS complain that there are two monitors unless they want to watch different shows. The other benefit to a center mount is that both rows can see them. Quite often we will go somewhere for the weekend with some of our kids friends, this means two more kids and it's hard for them to see the monitors in the headrest the way the seats are configured in the expedition.
Bottom line head to a nice electronics shop in your area and see what you like and go from there, either can be used for the DVD it's just going to be a personal choice.
