I agree with SoCal (for a change). You've invested a lot of time and money in getting where you are. To go to the US now will set you back, for a start, about a 1000 euros for the flight, VISA and TSA clearance. And then you haven't flown a single minute yet.
Why not search for a decent flight school in France? You need maybe 5-10 hours total to finish off your training and do the exam. If you spend a few hours phoning around (instead of sitting on the plane to the US, or sitting in the US embassy lounge waiting for your "interview", or doing any of the other time-consuming things that you need to do to go the US for flight training) I'm pretty sure you should be able to find a school in France that has full-time instructors, good availability of airplanes, a location with a good chance of good weather, and which is willing to give you an intensive training. 15 hours should be doable in one week, and should be plenty to get you ready for the exam.
And if you really want that FAA certificate (as a trophy or to actually fly an N-reg with), you can always get a 61.75 "piggyback" one.
My French isn't all that good, but a Google search of "cours intensif pilote prive" gave me quite a few interesting hits, including these ones:
Cannes-Aviation - Pilote privé (PPL-SEP)
Devenir pilote – Formation aéronautique AéroPyrénées – Aéroport de Perpignan
Apprendre à piloter