we are Beijing SEO company located in Beijing as well as in Phoenix, USA. We already work with Arabic, English and Chinese websites and bring them on the first page of google, yahoo and bing within 4-10 month time.
As all its depend on keyword competition..
We didnt work on french sites before but.. but If you want us to do SEO optimization for french website, we need to hire somebody who able to speak, read and write french.. or if you have a person who can help with it .. then that will save us time and money
Let me know more details via PM if you are interested..