Just how much powder was the OP talking about storing? Sounds to me that if he will be storing less than 20 lbs, then the elaborate spec. containers are a moot point. I'm storing about 8 lbs total at this point, I just use a wooden kitchen cabinet I picked up at a yard sale.
“At the core of liberalism is the spoiled child – miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosophy of sniveling brats.” — P.J. O’Rourke