Our clients are using it cpanel, plesk and Directadmin. But its not the which controlpanel... its your host restrictions and features offered...

But be sure that cron and forwarders available to you for follow up autoresponder and cron for iPassword protection pro. Forwarders are for email piping, so you can setup email un/subscriptions. (but this is optional. Follow up Autoresponder Pro works fine even without email piping through Form subscriptions)