Most root stock is available for comercial use & the bundles are usually 100's You can start your onw from seed then graft on the next year. As for apple/peach etc the root stock for semi-dwarf or dwarf are very special lines & I know of no retail source.

Now is a good time for you to contact your local chapter of the California Rare Fruit Growers. www.crfg.org will get you to the chapter in your area. There you will get information on rootstocks suited to your area and species and where they are to be found. In January each chapter puts on grafting demonstrations open to the public,membership not required. Scion wood is also offered for many varieties of fruit trees. Some member grown rootstocks may also be offered. All this is offered free or almost free by people passionate about growing fruit. Al