Also, I have a number of military ammo cans, military surplus, of course. The outsides are sometimes rusty which steel wool and WD40 takes care of. But ALL of the insides are rust free, if the can was kept closed apparently. So I think these are the ideal solution. If you want to store them under your bed in the climate controlled house, that is perfect IMHO, and makes use of space seldom used. As a bonus you can't do vaccuming there anymore.
I do like the plastic cans from Harbor Freight, too, but I am not sure they seal like the Army cans. They would work well under the bed tho.