CC I agree on the mahogany. I want to say that the spanish cedar aides in maintaining a consistent himidity level by absorbing moisture and releasing moisture when drier air is present, but all wood would do that at some level.
I would also state that you would want a very dense or hard wood for making a humidor with as a humidor is a torturous environment for wood and will test all the joints in a box or cabinet.
I was thinking of what I wanted to use for the floors of my walk in, i was thinking of doing a tile mosaic of the Gurkha legend band on the floor, but I may use ash or mahogany