I suggest going into an electronics place like Best Buy and talking to their audio folks. There are a number of options out there because many SUVs and minivans have DVD capable head units.
I would definitely look for one that's also blueray capable as we often get movies from a Redbox and sometimes the one we want is only available in blueray. You may not notice much difference on a relatively small TV, but it's nice to have the capability.
Let us know what you decide and maybe a picture of the new unit installed will inspire some others to do a similar project.
Manny and Larissa
2013 Winnebago 2301BH-Red
2012 Ram 2500 Megacab HO CTD