I have 6 orchids planted in my tank. They've only been there for a couple weeks but already every single one of them is putting out new growth, and my Pleurothallis coniculata is budding and my Dryadella edwallii had bloomed.
Andysorchids.com is a great place to look. They give you lighting, temperature, moisture, mounting and flowering information and are VERY helpful.
Some bigger orchids will work just fine but the mini orchids they and other companies have are awesome! They can be expensive but the ones I have are thriving in my terrarium environment.