'Ultra-budget':
http://www.hotelf1.com/gb/home/index.shtml
Better:
http://ibisbudgethotel.ibis.com/gb/booking/map-search.shtml
Citotel works in the same way that Best Western does. i.e. it's not a 'chain' but lots of independent hotels which trade under a common banner:
http://www.citotel.com/
Having mentioned Best Western, it's worth remembering that they have hotels in France too:
http://www.bestwestern.fr
However the place that I'd start looking (particularly with a large family group) is here:
http://www.hostelworld.com/
Don't be put off by the word 'hostel' in that URL. There are loads of good quality hotels on that site as well. (I used that site last year to find a lovely, superbly-located little hotel in Madrid, where a single room cost me just €22 per night)