I lived in the south of France for a few years. Try to get a "package" which includes tax support. Officialdom in France is very very slow, and very very difficult to work with. It is very helpful if you have some assistance on this side. When I left, it was two years before the authorities there were able to wind up my accounts and clear my taxes, even though I paid up well before I left!!! Mt tax assistance came from Price Waterhouse, who were very professional but like all others unable to get the wheels of government in France to move quickly...
Oh, and by the way, taxes there are very expensive! Do you have an equalization package?