Answer: I've always called them "soba" noodles, but when I searched the internet I found reference to "sobo" as another way of spelling those noodles. Soba/sobo are made out of buckwheat flour, so I am guessing that this is what you are looking for--the type of buckwheat used to make flour.
Buckwheat flour is commonly made from the buckwheat with the botanical name Fagopyrum esculentum. Generally buckwheat is grown as a commercial crop--I have a feeling you'd need to have a lot of room to grow any significant amount. The plant does require warmth, and is frequently used as a cover crop because it grows quickly and will shade out weeds. You can purchase seeds (intended for cover cropping) from Peaceful Valley Farm Supply, http://www.groworganic.com/ --they might have more information about how to grow and harvest for food.
Here's an interesting web site, all about buckwheat:
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