If you look back at the first answer to your question you will see I linked two Insignia's. One was the 20" which other's have pointed out will work. I also linked a 24" which would work as well and if you can fit it is a size that you would probably be happier with. Like the 20" it also has a 12v input. You would either need to purchase or make (very easy to do) a 12v plug. I actually have the 24" in my TT bedroom. It does not get a lot of use but it has worked quite well.
The biggest drawback with the built-in player is that it will not play blu-ray so if any of your discs are blu-ray you would still need a seperate player. Even though DVD's may be going out they still have an advantage in certain situations. One of those would while camping in a remote area that does not have wi-fi or cell phone reception. Another option would be to copy and convert your existing dvd's and put them on usb or portable hard drives. Doing this is dicussed here,
DVD copying thread.