There are so many good deals in the supermarkets for TVs with built-in Freeview (and usually a DVD player and HD ready) that I would be inclined to go down this route. At the moment the sets are built for both digital and analogue so if you are in an area with no digital signal, you can revert back to analogue.
I think your bigger problem in a touring caravan will be getting a good digital signal. The Status 315 (the circular disk type aerial on the caravan roof) will, almost certainly, be useless. If you have the elongated version, the more directional Status 530 you may be OK. I have had mine for nearly 3 years and have never failed to get a decent picture. A lot of people revert to setting up a free-standing aerial and erecting some kind of pole. If you're starting from scratch this is probable the most cost-effective solution. Take advice on which aerial to buy as they come in 'groups' and if you are going to be travelling all over the country you might want a wideband aerial - Group W.