I'm moving a thread that began on the D.C. Board about making goat cheese.
New England Cheesemaking Supply sells cultures that can be used to make a wide variety of goat and cow milk cheeses at home. These vary from chevre to mozzarella to aged cheeses, as well as creme fraiche, sour cream, yoghurt, and buttermilk. They also sell other cheesemaking supplies including enzymes and the cultures to give the coating on brie and such.
You can order by phone 413-628-3808 or likely through the website, which I've attached the website.
I use the one-time culture for making goat cheese rather than the one that you need to keep going like you would sourdough culture. I also make buttermilk, sour cream, yoghurt, and creme fraiche. These are all very simple. I haven't yet ventured into the more touchy aged cheeses.
They also provide a lot of information and advice, which is helpful. Some of the cultures work with pasturized BUT NOT ULTRAPASTURIZED products. Others work only with raw milk.