This guy's in Virginia, just read about him in "The Omnivores Dilemma" by Michael Pollen. He runs a pristine operation and I would definitely visit if I was there....
I DO have a suggestion re: probiotics. Mix up food sources...yogurt AND kefir if you do dairy. Kimchi and sauerkraut, both are easy to make, or a widely available "live" brand is Bubbies. All of these fermented foods have different microorganisms....
You could also try some echinacea to support your immune system....