One thing to look out for, is check the specs of the car you're thinking of and make sure it will actually tow what you want. A few years ago I was looking at a big 4x4, much bigger and chunkier-looking than my Jeep. Checked the manufacturer's limits on towing and it wouldn't pull my 1400kg van.
So read the manufacturer's specifications, never assume anything! Oh, and even if buying new from a manufacturer's main dealer, don't assume the salesperson will know the ins-and-outs of towing requirements, check for yourself.
And as others have said, remember you're likely to be driving without a caravan far more than you're towing, so make sure it's appropriate for your day to day use as well.