Côtes d'Armor
Windy all the year with stormy month between October and February. Optimal with a NW wind, you will find large beach with huge kicker. It's the Clément Huot training area.
Morbihan
Really nice area with a SW stream, windy all the year, strong wind the winter. lots of spots around, flat or waves, you will find what you are looking for!
Finistére
Very broad range of possibilty here, from North-East to South-West, it's a paradise for kitesurfers, flats spots, or big bay with kickers! Lots of cars between spots, a van is a good options to enjoy the area