Join the club... I get blank stares whenever I ask for Pothos here in South Africa, and when I show them photos they all point me to philodendrons.
And I currently have a large Hibiscus, but it is now thoroughly infested by aphids, and is going into quarantine until I can get rid of them.
In my experience, Schefflera Arbicola is a great plant in chameleon cages: tolerates low light and high humidity, and creates nice thick foliage for hiding. It should be a staple in any chameleon cage.
The other plant that I use is Ficus Benjamina. It can be a tricky specimen however. It tends to drop a lot of it's leaves if the lighting conditions change (making it awkward when you first put it into the cage), and it grows a bit lanky/top-heavy under the poor lighting conditions (by some plants' standards) in the cage. And also, the sap that oozes from the stems after pruning can cause eye-irritation to your cham (so do your pruning when the cham is not around).
Even so, it has a nice climbing structure and reasonably dense foliage, lives a long time if cared for, and tolerates high humidity, so it's popular amongst cham keepers.
I am currently experimenting with Camellia, and Bougainvillea (getting good results with small specimens placed high up, close to the lights - and my Veileds seem to favour the leaves of this plant), and using Fuschia (though these seemed to react badly to high levels of water).
I also have lemons and limes in my outdoor cage, but I don't think they'd fare well in the indoor lighting conditions.
Other plants that have been recommended are Dracaena and Croton, but they are mainly leafy, so are added just for foliage denseness and colour, not really as a substitute for Hibiscus.