This is one of my favorite sites:

http://www.cmsmatrix.org/

You can compare content management systems by features, language, pricing, reviews, etc.

Here is one similar that allows you to try out open source software available from their site:

http://www.opensourcecms.com/

In my opinion and most people that I have worked with in the past there is no perfect solution when it comes to a CMS. It is either too bloated or too bare. I'm yet to find one that I'm completely satisfied with, without some real coding involved. Out of the box installs just don't do it for me.

With such a heavy emphasis on the forum, have you checked out to what you can do with most forums systems modded out nowadays? Might want to check out the plugins/hacks listings for vBulletin, phpBB, and Invision. I don't know what your level of experience is, but most mods are simplistic. For all the features that you listed above, I think it would a good second solution.