I've used a MistKing system for many years. One of the nice things about it is you don't lose the settings on the timer when the power goes out. And as ES says, you can choose any size vessel for the water tank. I originally did the "starter kit" and bought extra misters and hose because I use it in a much larger area. Same unit has been going strong for around ten? years.
Make sure you use pure water (RO, rain, distilled).
Mistking
Looking for a misting system? Look no further. Automated misting systems from MistKing are used by multitude of plant enthusiasts and are perfect for Orchids. Systems feature run dry pumps, ZipDrip valve, adjustable black nozzles, per second control! Automatically mist one growing shelf or a greenhouse full of Orchids.