seperate databases

I'm looking to configure:

• 1 Drupal Base core
• 1 Core of set modules
• Under the core install many websites that have their own DB and possibly their own modules. I don't need them to share users or content.

My assumption of what the directory tree might look like:

Drupal_Base/
-Sites/

              --all/
                 ---modules/
                            ----views/
                            ----cck/
                  ---themes/

             --abcxyz.com/
                             ---modules/