Well this is it.
After several weeks of searching the entire web, and browsing this amazing forum for infos and advice, I've deciced to take action, and just bought my first mechanical keyboard: a Cherry G80-3000 LPCFR.
Apparently, this is the only mechanical keyboard still in production with a French layout. And it's sold by just one retailer in France
It cost me 80 EUR, which is a fair price I guess.
As far as I know, the model I'll be getting will have MX black switches. I hope I'll be satisfied with this.
I'll let you know as soon as it gets here !!
Thanks again to you guys for your precious advices !