I have set up Centos 5.1 Perfect LAMP + ISPConfig 2.2.3 + suPHP. I've just moved from WAMP to LAMP so I'm new to wrestling with .htaccess and mod_rewrite (but I figure it can't be worse than trying to get pretty URLs out of IIS

). I want to install multiple CMSs and am wondering how to plan them within my server's infrastructure - what to do at CLI and what within ISPConfig's structure.
I need a bunch of Wordpress sites, one WordpressMU site, and several Drupal sites. I have found a few threads about ISPConfig/Drupal or ISPConfig/WP but nothing about multiple *different* CMSs.
Can I set things up with only three code installs, without sacrificing security? That would be ideal.
- one reg. Wordpress install feeding many sites, each with their own wp-content (themes, plugins etc.)
- one WPMU install serving one domain, many subdomains, same choices of themes and plugins but different content
- one Drupal install feeding several sites, each with their own themes etc.
I am planning a second server (same setup) very soon so if it would be better to split this up over two machines, what would be the best way to do it? (where best = most secure and simplest to administer)
Finally, if I'm already tugging at things to make the multiple CMSs work, could I also set up Roundcube on port 80 with pretty URLs according to this tutorial
http://www.howtoforge.com/roundcube_webmail_ispconfig
or would I just be complicating things ridiculously?
Thanks!