I've seen people use the plastic bins/trays that you would use to hold pencils and stuff to hold singles. Personally, I have a few old boxes that I toss singles into. 5-packs, either put the cigars in a box, or just open the bag and toss it in the cooler somewhere.
For a 75qt cooler, you probably don't need oust fans.
----EDIT
adding picture of plastic basket/tray to avoid confusion:

6"x5"x3"