building a coolidor

Well I'm running out of space in my humidor and I'm figuring the cheapest route would be to build a coolidor. I don't want it to be huge. But do I need to tape cigar box panels to the sides to absorb humidity? Or I would like to be able to just put the cigars in cigar boxes and maybe put a shelf on top for any loose singles. Would that be okay? And as far as a humidification device goes can I use maybe one or 2 of these? http://www.tampahumidor.com/accessor...chanic-250.php.
Thanks for the help, I'm still a bit of a newb but I'm trying to learn as much as I can.