Hey Jamie,
The ficus will work great from what I have read, minus the one issue being the "sap" that a chameleon can get in its eyes from rubbing on the branches. I bought one but never used it because it was too tall for my 4ft tall cage, so I bought a hibiscus (which is 3 1/4ft tall in the cage) to put in there. I personally prefer the hibiscus and recommend it to anyone for their cham(s) for many reasons.
Some sites say ficus is better, some say hibiscus. I like the hibiscus because of its fullness; its thick and strong. It also blooms a nice looking flower that comes and goes quite fast. My chameleon loves it and thats the only plant I have in there for him. Hopefully I can throw up a pic sometime soon in the gallery so you can see it.
PS... whatever plant you choose, wash it off thoroughly with soap, and replant it with perlite-free soil. Cover the soil with some screen, or put big enough rocks (that the cham cant swallow) directly over the soil. Hope this helps some...
Jim