I have to agree with Mamba, a 120qt cooler is perfect, but if you are looking for something with more pizzazz to showoff....go with the Galleria or Lauderdale, but they do not have built in humidification system, but a couple of lbs of beads will be perfect:
http://www.cheaphumidors.com/humidor...-humidors.html
They used to have an "Make me an offer" option, but I'm not sure if they do or not, but when I got my Tower I offered them 15% which they accepted.
If you don't want to go the beads route you could spurge & get the Set It & Forget It from Avallo
http://www.avallohumidors.com/Accumonitor.html