If you are buying in France why not try Nicoplast? Not Langstroth and certainly not cedar but an interesting product. At least the locals won't be able to blame you for being unpatriotic. Their hives are a sort of French BeeHaus but designed on a more practical model.
Heard about a beefarmer with about 450 colonies today. As he goes through his apiaries he is slowly culling all the old rotten wooden hives and replacing them with poly. He plans to do this over several years. The hives are quite old so this is not a viable strategy for those with younger wooden hives but the point is he has no plans to replace wood with wood. Beekeeping efficiency is vital as he is running a business.
However, if you are set on wood there are any number of suppliers including folk on this Forum and I would be happy to recommend the forum suppliers if wood it must be. They get good reviews.