R – Creating a custom content type in drupal

The simplest solution for Drupal is to use the Upload module, which is in core. The upload module allows you attach files to nodes. As you note, they are stored in the filesystem.

If you want to get more complex, you can build your own content types through the web interface by using the CCK family of modules (such as the filefield module or the imagefield module). Your files are still stored on the filesystem.

You could use CCK to create the metadata field you want.

You could use the workflow or rules modules to implement workflow.

IP information is recorded automatically by Drupal's logging module (either the database logging module, which logs to the database, or the syslog module, which logs to syslog).

URL aliases for nodes are available in core Drupal by enabling the path module (or download the pathauto module for automatic creation of aliases).