If you go for a gas stove, you will find that canisters for screw-on stoves are not that widely available in France - you generally need to go to an outdoor store or a sports store such as
Decathlon or Intersport.
The Camping Gaz canisters are widely available in village/small town supermarkets, the pierceable ones a bit more so than the click-on (CV270). CV270 look like they would fit, but have no screw thread for regular UK gas stoves.
I'd suggest either an
MSR Superfly, which will take either regular screw-on or Camping Gas click-on, or getting the
Vaude adapter to use a screw-on stove with a Camping Gas click-on canister.
Trangia plus gas adapter strikes me as being a not very light gas stove with a very large and heavy windshield.
If you go for a petrol stove, bear in mind that car petrol will clog up many petrol stoves, and that "white gas" or coleman fuel isn't that easy to find in Europe. Having said that, a litre bottle will last 2 weeks if you are careful (and not flying).