Alternatives to MediaWiki + Wordpress + Coppermine + phpBB

Ok, i'm running a number of virtual hosts each running 2 or more of the above services. I am serving about 6000 requests a day quite successfully at the moment, i've only really hit problems when I've done /very/ silly things like a COUNT + JOIN + GROUP BY on some 60Mb tables.

I am looking to make my life easier by switching my 'off the shelf' products for ones that do more than one of the listed functions.

The ability to import data would be a bonus, but this can always be hacked together with some effort. I do a lot of python, java. SQL and perl, but very little php.

I think Drupal and webGUI have the features i would need, but I have a feeling they may be too resource heavy (like requiring 500Mb + ram)

Has anyone had any experience with any of the more sophisticated CMS systems on a linode?