French Healthcare / Citizenship (Toulouse)

I am hoping someone can help us with information regarding residency and healthcare. We will be moving to France within the next 6 months to a year to retire. My partner is a UK citizen who has been working in the USA for the last Protected content , I am an American citizen. We plan on purchasing a home outright and would be very interested in obtaining French citizenship. I understand we will need to purchase private insurance for at least 5 years and wondered under what circumstances we would be eligible for the Franch healthcare system. We have searched the internet and found many conflicting answers and need current, accurate information.

Thanks in advance for any advice you may have!

Anne