Doug wants a 12v TV for his RV that's about 24" in size. Leo says he could get an inverter that can convert the DC to AC. It'll drain the RV battery though, so he should be aware that. Dish has special RV packages too that aren't too costly. But as long as he's near a metro area, he can just get an antenna and get the best resolution since it's uncompressed.
Doug should check out my12voltstore.com to look for a TV.