Rennes is loaded with young talent.
So is Monaco.
Lens also has a good future.
Even Marseille (!!)
This will be a fun year managing in France, you can even try Strasbourg with their new affiliation with Chelsea.
Montpellier got elite prospect like Esteve and Wahi, but I think Bordeaux is a great choice, good young players and a fallen giant (use to be Zidane team lol)
I do think thats a start, not the realistic solution though, in Spain they rarely loan out players, because of B / C teams.
The problem is that playing in those teams doesnt seem to help player development as much as it does in real life