You can use any of them, you just have to plug the drain and use some sort of humidification device. Lots of guys unplug their wine coolers in the winter, doesn't harm a thing and it extends the life of the unit.
I think the draw is that they look very nice, especially when they are all pimped out with drawers and stuff. A fridge, not so much. A fridge isn't very sexy for showing off a very expensive collection, ya know?
Have fun, brother!!!