Hi- I don't know how many birds you have or how big your "truckload" is but I buy my feed 150-200 lbs at a time (about 25 birds/lasts about a month) and store it in 2 large galvanized metal trash cans. This keeps out vermin and weather; I don't want to get larger quantities because I don't want any to go to waste if it should somehow get damp or otherwise damaged. I also don't want it to get "stale" so the birds have the freshest food possible.
i too use gal. trash cans. as mentioned they hold 150 lbs apiece. and thats all i buy at a time. ive been told in other climates, the gal. will sweat. and ruin feed. i havent ever had problems with that....but something to keep in mind depending on where you live and where you store your feed.
yrs ago i used the plastic trashcans. a squirrel chewed the bejesus outa the lids and got into the feed. im sold on the metal. even though they arent weather proof like the plastic cans.