"Both those gyes stated that they are both outdoor plants."
I'm pretty sure you'll find that ALL plants we use for chameleon enclosures are outdoor plants.
There are two reasons for this:
1) Most of the world's plant species existed [outdoors] long before we humans ever turned up to build houses to keep them in, and
2) in the wild, chameleons live outdoors - in trees, mostly - and hence in captivity we try to replicate a natural environment as best as possible.
I don't think it is reasonable to expect any plant to thrive for a long duration in a chameleon enclosure, or anywhere indoors for that matter. Sure, there are plants that do quite well indoors (like Pothos - my office in the city with no opening windows is a testament to that), but in the right conditions (like their natural environment) they do even better outdoors.
So the key to keeping these 'outdoor' plants successfully is to rotate them between your cage and outdoors. A good period outdoors will allow them to recover enough to be placed back in the cage after a while. Most keepers will recommend that you have spare plants in case anything happens to the ones in your cage (plant diseases can strike suddenly), and these are the plants you will rotate with the ones in your cage.
Also, I find many similarities between keeping plants in a chameleon cage, and the art of Bonsai. The basic principle of both is to keep healthy plants within a confined shape/space. I think you'd do well to get a book on Bonsai to learn some of the techniques used to keep trees in confined spaces. Plus, the shaping techniques will also help to create the structure that you want to provide for your chameleon.
As an interesting side note, although it is recommended that most bonsai species be kept outdoors, Ficus is one of the species that is often suggested as an indoor species.