rail dvd player

Hello everyone, im sure you have hered this question before but i havent gotten an answer from what iv read, so here goes.. I have a 2004 FX4 with the rails on the roof. i would like to put the DVD player on it. Is my truck cabible of a dvd player is it wired for it? And were can i find an oem dvd player for my truck? iv looked all over but have not been able to find one. Any info is helpful and thankyou for your time.