Does anyone know of any tours of parma cheese or ham farms/factories leaving from Verona or Florence? Has anyone done it on their own with a car? Are tours in English?
Parma is south of Verona by about an hour and north of Florence by about two hours. If you want to take tour of farms, you'll need to base closer.
Take a look at www.foodvalleytravel.com and http://www.parmagolosa.it/parmagolosa/percorsienogastronomicieng.html. I think that you will find the tours you are looking for but I believe that you may have to be in Parma to begin the tours.
personally i would never pay for a cheese factory tour, because you can arrange one in English yourself through the parmigiano-reggiano consorzio for FREE. The problem for you is that they start making the cheese shortly after 8am because part of the milk used is raw and must be processed within a certain amount of time after coming from the cows. If it's that important to you, I would recommend staying a night in the lovely parma, from where it is easy to get a cheap (app. 12 euros from the main square) taxi to the dairy. Seeing the cheese made was truly a highlight of my last trip. I have a whole new appreciation for it and even though I probably shouldn't, I now refuse to buy anything but the "real" stuff.