Ficus benjamina is a popular cham plant. There is some evidence that the sap is irritating to a chams eyes, but that only happens if you break or trim off a branch and then the cham would have to rub their eye on it - not very likely to happen.
As for the kimberly queen fern, I haven't seen a pic of it, but if it's like most ferns, it probably won't support the chams weight very well. The fern will end up bent and broken I think?
I really like Schefflera arboricola - commonly called umbrella plant.