How to start an orchid terrarium?

[Botaneer]

I'm a newbie so please forgive me any mistakes!

I have a 60 gallon terrarium that I am in the process of turning into an orchidarium.

I need some advice onhow to proceed! So far I have a roll of coco-fibre mat for the backing of the terr. and I have a small fountian pump that I want to have a waterfall and small pond area in the terrarium. Anyone know if this would be detrimental to the orchids to have a flowing water source and a fairly wet environment? Risk of disease?
I also have a FANTASTIC source for orchids. Too good, since I lloked at their plant list and have no idea how to choose. I'm looking at paphiopediums since some are native in my area. Any suggestions on species that would do well in such a wet terr?

Thanks for any help!