King Arthur Unbleached Bread Flour bulk equivalent

Good morning,

I would like to buy the King Arthur Unbleached Bread Flour (this one) in bulk (25 or 50 lb bag). Does anybody know what name it has in bulk? Is it the Sir Lancelot, Sir Galahad, Special Patent? What is a good place/website to buy it? I live in Washington DC.

Thank you :)

Bea