I'm a little late on getting in on this one. Chipmunk script isn't too bad, myself I prefer Gossomer Threads Links 2.0 ( http://www.gossamer-threads.com/scripts/links/index.htm ) There is a free version, and it does require a few mods to have it provide a true link out, rather then a cgi jump link.

As for Forum, all agreeance with phpbb, also needs a few mods it needs to help get things going. I have only used one other (Ultimate PHP I hink it was) and it was slightly less limited. Another one that I will be getting into soon is http://www.simplemachines.org/index.php.