CCK Database

Hello,
I+'ve+ been using Drupal for about a year now, and have a number of sites based upon it. One of these has well over 20,000 nodes, and is run by an adaptation of the movie database module. However, this module seems to increase the server load exponentially, and has often caused my (albeit fairly low spec) server to crash. Therefore, I want to convert the content to cck content types (movie and person), with one being linked automatically to the other. I am hoping this will lessen my database queries, and help increase the speed and functionality of the site, as well as being able to upgrade to d6 at some point in the near future.

My question therefore, is how would I go about creating a cross referenced site like this - with content types being added and referenced each time a name is added? I know there are a few, but I'm really confused as to the best way...any help would be gratefully received!!