You can see all of the available Perl modules by entering cPanel and clicking the Perl Modules icon (under Software/Services in the X3 theme).
On that page, scroll to the bottom for a button to "Show System Installed Modules".
If you need more modules, please contact us via phone, live chat, or email support@hostgator.com with the names of the modules.
VPS and Dedicated servers are less restrictive when requesting/applying modules.