Auto page creation with WHMCS

I need to have an auto page created when a client purchases a product through my WHMCS software The flow would be 1 of the 2 options with the same end result Client signs up for a FREE product through my whmcs billing software version 4.2.1 The billing software using auto script install through Softaculous or cpanel ??? whatever is easier and creates a subdomain page ( will private message an example ) on this page is included the same design , colors , my google adsense code or banners system a flash player that is playing the music stream my whm sonic created , there website name will appear 2 nd option if your not able to do this through whmcs i would like a register form and then this subdomain page automatically created but remember you will need to make the system create the stream in whmsonic ( will private message an example ) looking forward to bids and this to be done quickly