Ian: you can create your own sourdough, or order a dried starter
from Sourdoughs International. You can use an incubator to start and
grow the sourdough (a disposable foam ice chest is useful), then
store it in the refrigerator. Shouldn't be much of a problem. Ed
Wood's books and directions from Sourdoughs International should be
invaluable to you--good, clear directions on both creating your own,
as well as using a starter, and then maintaining the starter. Peter
Reinhart's new book, Whole Wheat Breads, also has very complete
directions on creating your own. Happy baking!
Alan Woods
Columbus, Ohio, USA
http://alan-ohio-bread.blogspot.com