yeah, i too would watch the humidity and temperature. I might even place a humidification device in there just to be safe.

Regarding stocking the locker. I'd pull all types in there. Great thing about a locker at a cigar store is that if your buddies go with you to have a smoke, they can buy their cigars from the store and not mooch off you.

About the trays: I'd probably just use empty boxes. I guess you could go to the hardware store and fabricate some shelves, but I don't think I'd go through all that trouble.