Trying to convert your drawer to humidor is not that simple. The seal between the lid and the box of a regular humidor has a bevel that the lid slides over snugly. This probably won't be easy to incorporate in to your drawer unless you are a fairly skilled woodworker. If you are intent on going down this road, I would use solid Spanish cedar as opposed to veneer and make sure you get the lid seal right. Research hinges because most humidors use hinges that are hidden inside each side of the humidor (can't recall the actual name but someone posted pics recently in one of the sub-forums).

Personally, I would buy a desktop humidor from a quality dealer or if you are planning on expanding your cigar collection extensively, get a cooler as previously mentioned. I bought a 150 count humidor when I got in to this hobby about 8 months ago and now it's near capacity.

I won't be buying any more humidors as the one I have is nice and performs well. I may pick up a cooler and then just use my humidor to hold the cigars I plan on smoking in the near future.