Good news is that your advice worked. We have our own variation of Joomla install that we use and just zipping that up along with a SQL dump (replacing the db prefix with yours of course) worked great.
What isn't working is when we click the create button from WHMCS, the admin name and password from the custom fields we created per the WIKI aren't being inserted. The username admin/pass is being inserted instead.
WHMCS returns the fields in the same name that we have documented i.e. 'Admin Pass' comes to us as $params['Admin Pass']
Hence renaming them is not possible.
----------------------- For immediate support please email us at our Support email address. PMs sent to any Softaculous Team member or posting in the forums is not the official way to get support.
Virtualizor - The Next Generation VPS Panel
Webuzo - It is Softaculous Standalone for Enterprises, SMB, Developers. Deploy it on Dedicated Servers, VPS, Virtual Appliances or the Cloud
Pinguzo - Server and Domain Monitoring tool
PopularFX - Marketplace of WordPress, Drupal, Joomla, Bootstrap themes
Remote Installer - Use Softaculous over FTP/FTPS/SFTP