I think I got mine from Bob's Red Mill in um Nebraska? A five gallon pail was about 33#, delivered for umm $40?
Then it needs malting, tumbling in the clothes washer in a pillow case, winnowing the cyanide containing rootlets out, roasting, mashing (another trial!). All in all not worth the effort, it is still sorghum beer. But the bucket is a good one.
I think I did a step-by-step, search this forum for malting sorghum?
White sorghum is used as chicken feed, but I couldn't find it at any local feed stores. I did run all my left over through the malt mill and give to a neighbor for his chickens, but they wouldn't touch the stuff.
They will send you a 5 gallon pail full of sorghum grain. You can malt it/roast it/do what you want with it...but it is a lot of grain. Cheap too.
There is a sticky on malting gluten free grains and there is a link somewhere in another thread where I talked about ordering from Twin Valley Mills...can't think of it right now.