Or a portal.

Go to my site http://www.cgart.tk and see if thats what you like.

To get the portal go to http://www.xoops.org .

For other portals go check these out:
http://www.myphpnuke.com < with a simple built-in forum

http://phpnuke.org < what pcplayground uses i think. But ask tommy or someone where they got a version with phpbb pre-installed.

http://www.postnuke.com < i dunno if it has a pre-installed forum with it, but its cool too.

The best bet for the features you like might be myphpnuke in my opinion, but the forums arent too good. phpnuke has the most modules so you could probably find the addon feature your looking for with this portal. xoops has good built in stuff, easy to use and some good modules like a gallery and a blog. Check em all out and see what fits you best.