Hi Robert,
Perhaps the first thing to do is to dig out your Citroen owners manual and in the technical section, look-up the maximum braked trailer weight and the kerb-weight of the car.
I'm guessing that the maximum braked trailer weight will be around 1000 to 1100 kg, and that places a legal limit on what you can tow - so you'll certainly be looking at a lighter weight caravan.
I'm guessing that the Citroen kerb-weight will be around 1200 to 1300 kg - which if you've never towed a caravan before, there is a suggestion that you keep the maximum caravan weight to less than 85% of the car kerb-weight - or around 1000 kg
If it's just a caravan for you, and possibly a partner too, then you might want to look at Eriba, T@B, and other similar light-weight, functional and cute caravans.
If you want a more traditional shaped caravan, and don't want to spend too much money - then older caravans tend to be lighter than their modern replacements.
Look on the Internet for owners clubs, images and reviews - and see if you like what you see. Then take a look at www.whattowcar.com which will give a rough assessment of how your car and caravan will work...
If you need a caravan for a whole 2+2 family - then that's going to be hard with a 1.6 Citroen...
Robert