Had you started your quest earlier you might have been able to get into an UNTOURS stay, but it looks like they are booked at the times you stipulate. Maybe you have some flexibility?
Untours European Vacation Rentals - Vacation Packages in Italy - Tuscany
Untours sets up your location - villa, apartment, farmhouse whatever, for lodging, gives you maps and gets you oriented and then off you go. But, they have set dates for the use of the properties as one would expect.
Still, you might check with them to see if there is the possibility of your making arrangements through them. Maybe there is a cancellation. Maybe they can steer you toward another available vineyard /apartment/farmhouse in hopes of you using their service in the future. Maybe you can arrange your visit to be in Tuscany when Untours has an available slot?? Won't hurt to try.
As far as I have researched, they are reputable. When I go to Italy next year, I will be going with UNTOURS. I have a first hand review from a good friend who did an Italy trip with some friends through Untours and she loved it. I think they went to Umbria.
Here's some info:
WHAT'S INCLUDED IN THIS UNTOUR?
The Italy - Tuscany Untour Includes:
One or two weeks in a farmhouse apartment, often on a working vineyard with stunning countryside views.
Suggestions for booking your international flight from the U.S. to Florence, or we can purchase tickets on your behalf. (Click for more information on Untours' air policies.)
Airport meeting upon your arrival (set arrival time only) and assistance with your rental car pick-up and transfer to your apartment. (Or detailed instructions that allow you to reach your apartment independently with ease.)
Car rental, with unlimited mileage and basic insurance, for the duration of your Untour.
An orientation with our acclaimed local staff person, who is full of excellent recommendations for your sight seeing, practical advice on driving and parking, and a listing of local events happening during your stay.
A comprehensive driving map, local information, plus our own Untouring Tuscany guidebook, researched and written by Untours staff, full of the best restaurants, sightseeing, and other suggestions.
A local cultural activity, like a luncheon and a guided tour of a local abbey.
Use of an Untours cell phone while on location.
A stash of groceries upon your arrival, so you don’t need to shop right away.
Pre-trip planning advice from our staff, available by phone or email right up until you leave.
Ongoing support with our local representative. Help available when you need it.
I've used a similar service in Spain several years in a row, but for study at their universities, and it is an amazing service to have everything ready for you when you arrive. The costs IMHO are reasonable.