Was at Bass Pro Shop this past weekend, I will have a $25 gift card, should I get plastic ammo cans or the real metal ones? Plastic is under $10 while metal is 20?
Inspect each can though... surplus means different qualities. Check the weather seal under the lid, the snappiness of the clasp, and handle. Also check for rust.
Get military surplus cans, if you have any rust, wire wheel and prime and paint over them. I paint the exterior of all my cans, have for a long time. Don't mess with the inside, if there is rust inside, don't buy it. Most cans will have some minor surface rust on the outside. I steer clear of bent cans at all cost, and dents need to be small.
Otherwise, you can't go wrong. You will have a solid setup too.