It's easy to put together your own touring route. France is blessed with 2 great map sources, IGN (Institut Geographique National) & Michelin. My own preference is for the IGN 1:100,000 series, but Michelin maps are certainly more than adequate for creating your own route.
I've climbed Mont Ventoux, Col du Tourmalet, & Alpe d'Huez, all on my Bike Friday folder. Alpe d'Huez was by far the most difficult. Frankly, I did not enjoy that one, though the scenery was very nice. The gradient changes constantly and the very beginning is one of the steepest parts, which I found very discouraging. Mont Ventoux was fairly easy starting from Sault (the easiest of the 3 possible places to begin the climb), except for the last 4 or 6 kilometers. The Tourmalet was long but had nice scenery and a fantastic downhill that went on and on, all the way to Lourdes. I rode it east to west. I had panniers and there were a few hundred riders on a beautiful Saturday morning in late May when I rode up Mont Ventoux. I didn't see anyone else with panniers. A French guy on a road bike, noting my panniers, asked me jokingly if I was taking performance enhancing drugs.