Build your own humidor?

It would appear that I am/have outgrown my current humidor (just a 50 counter, and saying 50 is generous). It was kind of a clue when my 20 count "travel" humidor is now being used for normal use. So I am looking at building my own humidor because frankly all the humidors out there are too similar and I want to try something unique. Its not a question of ability because i have built intricate woodworkings before such as jewelry boxes etc but there are other questions that I have.
In just about every humidor I have seen there are no nail holes or filler putty spots so the question arises how do you secure the kiln dried cedar into the box itself? I could use a glue/adhesive but I don't want the chemicals affecting the cigars so I am at a loss.
Any suggestions on size/dimensions would be appreciated, Im leaning towards a 150-200 count humidor with 3 levels and trays at each so i can separate out by wrapper/flavor. For each level should i put a humidification device or would it be better to use one big one and router out vents into the trays?

Also any other input would be appreciated.

Thanks,
Danny