The Digi chorus and flanger have always been Audiosuite only.
EGS already listed the only free stuff I know about.
Some other chorus/flanger plugins include:
Waves MetaFlanger
Nomad factory Liquid bundle
..and a few others.
If you've got the VST-RTAS wrapper, the choices increase exponentially.
You can also create chorus and flange effects with the stock delays, but that takes a little bit of work and know how.