Almost all modern TVs have a standard VESA mount on the back. The box formed by the screw holes is typically, but not always, a square that is 75mm, 100mm, 200mm, 300mm or 400mm on a side. There are adapter plates.
I like Monoprice for a lot of A/V stuff, and here are a couple of adapters they sell:
Bracket Universal Adapters - Monoprice.com
Their TV mount products seems to be on-par with the mounts you'd find elsewhere, but cost much less. I've purchased a couple for my house and my company has purchased a lot as well. That said, most of their mounts aren't specifically designed for RV use. To my mind, you should have a larger wall plate so it won't pull off the wall while underway, especially if you don't have access to a wall stud and are just screwed into a piece of plywood, so that limits your choice of articulating mount (I like this one for that reason: http://www.monoprice.com/Product?c_i...seq=1&format=2
). Most of them also lack an integral locking mechanism, so you'd need to secure your TV with a bungee or something.