Does anyone know a good community application written in PHP (or ASP)?
We'd like to have a management tool to build: channels, profiles,
forums, who's online, discussion boards, clubmail, etc. A good Dutch
example is www.clubs.nl. This one is custom build by a Dutch web
agency. Users have to pay to open a club or post a message. This will
not be needed.

We have inhouse PHP knowledge, but we do not want to build an entire
website and management tools. We'd like to launch in 2-3 weeks.

I think that http://www.ikonboard.com/ offering you the best software
you need.  You can gat an exemple to this link :
http://directory.myikonboard.com/

I hope it's whats you seeking for ;)