Glad you found your Tuscan villa and really excited to learn that you know about Servas! I am always recommending it to folks as so few seem to know about it but it is really an awesome way to travel. It's free accommodations anywhere in the world and the opportunity to meet new people and make friends that you'll likely keep for a long time, as well as get a better insight into your desintation by having the connection to locals.
I'm just so glad to finally hear of travelers who are going to be using Servas for in-home family stays virtually any place in the world. Servas does screen both Hosts and Travelers and one does NOT need to become a Host if one wishes to become a Traveler, it is only optional if you want to Host. All members are interviewed in the many Servas locations around the world, applications are filed etc. It is very safe and a lot of fun, not to mention a great money saver.
Good luck with your Servas membership process! For those interested in learning more about the organization (a non-profit) go to www.servas.org