How hot does the steam room actually get? Cactus, but they need more light. Hmm. I'm stumped. Most tropical plants start getting pretty stressed above 95 degrees, and I can't imagine them living in low light and extreme heat for very long.

A silk palm will do just fine

uuh, don't think the cactus would enjoy the high humidity.

perhaps you could switch them out every few days to get the sun. do you have a place with sun to put the plants?
Hibiscus appreciate heat and humidity but only if they can be moved out to a bright location every few days. ferns also like the humidity(only with light). stay away from succulents and poinsettias as they like a dry almost arid existence.

Hibiscus don't enjoy being moved frequently. They will sulk and throw yellow leaves.