I only grow a couple of miniature orchids. My mini's are from the Barbosella genus. However, I would suggest you really read its culture first since, these ones, prefer colder temps. I can only get them to make some blooms when it is Fall here, though it is not in a terrarium, just mounted. Or you can read more about the Pleurothallid alliance orchids..there are lots of them..pretty sure there will be some that will love warm terrarium temps.
Barbosella cogniauxiana pink
Barbosella australis
Pilea involucrata 'Moon Valley' has showy leaves and nice little blooms..
