I love french campsites. Great facilities, well located and often with amazing shops / restaurants on site selling incredible local produce.
We've done lots of camping in France with our two young kids and loved the Huttopia sites and also the Castels sights. We've always just taken our tent, rather than booking one of their other options to keep costs down.
Here are a few ideas:
This one is brilliant and very drivable (but no pool): [www.campinglebrevedent.com
This one was close to the Brittany seaside: [www.keravel.com
This site is probably my all-time favourite. Located on the beach, you can head out and dig your own oysters. We hired bikes with kids seats and explored the whole island on bike - totally stunning! We are heading back there this year: [europe.huttopia.com
Hope this helps!