Hi Ladynade,
I can understand your concerns wanting to find a safe and friendly area to live in France, especially for your kids. As you mentioned visiting beforehand is probably a great idea. Also, remember, racism exists everywhere it's impossible to escape bitter & twisted people.
I am a single black UK woman who's traveled all over the world (almost) including China. I now live in Spain and have never experienced racism in Spain, China, Germany or USA, only in London. That's not to say it doesn't exist here.
If you respect your new culture and learn French hopefully your move to France will be easier. And if anyone dares to abuse you in French you can return a few **** You ******* words.
Best of luck