Go to Best Buy and look at the TV's there. Ask salesman if the one you like the best or fits your budget has an external transformer. You will find lots of brands that are using 12 volts as a power source with a step down inline transformer You then just buy the appropriate cord for less than $10.00.
VOila a 12 volt tv. I have 2 in my MH that I did just this.
One came from Walmart and is a Sceptre the other is a Best Buy Insigna brand.
Make sure you look at the TV from different angles in the store.
Traveling with my best friend my wife!