And I just thought of another one that I currently have in my cage: Bougainvillea.
In the right conditions, they will keep their leaves year-round (although where I live they tend to drop leaves at the first sign of frost in winter). And they generally flower quite abundantly.
The other benefit of Bougainvillea is that they grow strong, woody branches. If you get a variety that creeps, it can grow fast, and provide quite a nice climbing structure for your cham.
I'm not quite sure about the long-term practicality of Bougainvillea though. Although they're also included on the 'safe' lists for reptiles, I'm not so sure whether they'll thrive in a cage. They prefer to have soil that's more on the dry side, and I think the light might not be strong enough to get them to flower.
Having said that though, my plant has just sprouted a whole bunch of new leaves after being in the cage for a month, and it actually seems to be growing quite well.
It'll take a few more months before I can be sure though.