It might be helpful to know where what airports you might be flying in and out of in France. Keep in mind that Nice and Marseilles are both international airports with non-stop routes to JFK, and Paris is the other option.
I'm a fan of the Cote D'Azur and it's easy to travel outside whatever base you choose. All of the resorts between Cannes and Monte Carlo are wonderful, and here's how I get around:
Also, have you thought of traveling to Normandy or have an interest in visiting the D Day sites. The experience is moving and we have combined a Normandy/Paris/Cote d'Azur trip in ten days. You will have more time. The distance between Provence and Bayeux, the base I would suggest your staying, is not short, but you could do it training it to Paris, maybe spending a day there, and taking the train to Bayeux. Below is a link to how we did out trip, arriving in CDG in the early morning, taking a train to Bayeux, and what we did from there. We didn't make it to Mont St. Michel, but MSM is only 1 1/2 hours from Bayeux.
If this appeals to you at all, I would suggest that you arrive in Paris, travel to Normandy first, travel back to Paris for a short stay or just an overnight (you can go wrong with a stop there!), travel on to Provence and fly home from one of the southern airports. Most people would say "Whoa! too much!," but with Paris in the middle, it works. A day's travel between Avignon and Bayeux would not be my recommendation, but breaking up our journey was nice and I don't see train travel as "down time." Some of our best travel experiences have been when we've traveled by rail and the legs I'm suggesting here will be a few hours. Give us a butter and jambon sandwich on a baguette and coffee or a bottle of wine (especially a Provence rose!), and we're good to go! I'm only familiar with Bayeux, Honfleur and Deauville/Trouville, but if you get on the Normandy forum, others can help you with places you might want to visit in both Normandy and neighboring Britany. With a car, you could travel back to Paris through Rouen and Giverny, but I wouldn't suggest that on the onset when you'll be jetlagged.
You may be on guidebook overload, but here are two more that might help you with your planning:
“Frommer's 25 Great Drives in France (Best Loved Driving Tours)”
“Back Roads France (Eyewitness Travel Back Roads)”
These books kind of "connect the dots" between the places that appeal to you in other references. If you can't find them in a local bookstore, they are available on Amazon.
BTW, here is a post about to avoid some of the quirks that befall American travelers when we view and book our tickets on French train sites:
Have a great trip!
Edited: 5:21 pm, December 07, 2012