Back to the subject
As usual thread creep has given you a bunch of opinions that you did not ask for and one post that you did not need.
To pick up on what Rod1 had said...............
There ae very few non- complex 160HP aircraft that will lift the payload that you require along with a nice fat fuel reserve, the only one that springs to mind is Robin DR400/160.
The Robin would lift the payload and fuel for the trip you plan to Le Touquet and probably also lift enough fuel for the return trip.
If you can find a DR400/180 so much the better,that will do Oxfordshire to well south of Paris with 4 normal adults or Oxfordshire to northern Spain with 2 adults ( both including life raft & light baggage).
Oh and the last thing the Robin will do the trip out off a runway about 30% shorter and is 10-15 kt faster in the cruise.