If I had the opportunity and the where-withall, I would hit France first. Simply because, as you said, you can always drive to Quebec anytime. As Highthief pointed out, both are unique, and have their must see attractions. I've been to both, but it France was back in '78. I still can remember the sites, smells and sounds of Paris, and think that it should be on your list.
all parts of Quebec are fascinating, but you will probably enjoy the urban experience more. The restaurants and nightlife are fantastic. If you are in Quebec City, you have to try the creperie beside the Chateau Frontenac, and the Aux Ancient Canadien restaurant just up the street.
http://www.auxancienscanadiens.qc.ca/Homeang.html
I had smoked pickeral there.