Possible Duplicate:
Which Content Management System (CMS)/Wiki should I use?

I am working with a team to select a new content management system for a large membership organization (around 25,000 members). The organization has revenue so I'm not looking for a dirt cheap solution.

The site currently uses ASI iMIS which is based on ColdFusion. It's difficult to work with and not flexible for our needs.

What other possible alternatives to ASI iMIS are there?

Ideally the solution would have some sort of support from the vendor.

So far I've come up with:

• Drupal/Acquia

• SDL Tridion

• Plone

• Ellington (probably too news like)

• Pinax (probably not developed enough)