Luca, I installed Neotech 4003 mains from my consumer unit in a UK 230v system. It's rated 27A and very flexible.
For two longer runs (for AV and modem) I used the standard Belden 19364, which is a bit stiffer. I use some Supra Lo-Rad for power leads and it is even stiffer, but built for durability.
The 4003 is silver plated OFC with a drain cable, there are UP-OCC versions.
Mains Cable
www.hificollective.co.uk
I got mine from HiFi Collective. You can get samples, may be easier to get from Audiophonics in France.