Pothos is a must IMO. It can be hung, or set on the floor of the cage.
A ficus is great, they apparently inhabit hibiscus in the wild in Hawaii, both ficus and hibiscus can be "tricky" to care for though. I have mine under a 6500K plant light, and they do fine.
Solid Snake Thanks for the idea's on the plants I will check them out and figure something to put in his cage with him!! We are loving watching him change from the dark black/gray that he was when we got him to a green color I think that means we are doing something right!!!
Go to FL chams website. They are a site sponsor. Look up their live plant database and print it. trust me PRINT IT. Then just take your list to Home Dep
or Lowes into their garden section and find a plant you like... then see it it is on the list. That is what I did. Makes it a lot easier.