Most quality woodworking stores carry spanish cedar. As far as coolerdors, I have two 48 quart dors, one with a spanish cedar lift out tray and one with a luan lift out tray (luan is a common mahogany laminated wood product that home interior doors are made of and is carried by all lumber yards in 1/4"). They serve two purposes, one is to give me separate storage areas (upper and lower) and to keep my dor from being over humidified. The wood absorbs and releases humidity like your humidifier. A coolerdor with no lumber in it is hard to maintain to proper humidity in my limited experience, so add a tree or two. Steve P.S. you will be surprised how little humidification it takes to maintain these! And how maintainence free! All for $13 from Walmart.