automated installation script

Looking for a automated website based installation script like the ones found in cpanal to install php scripts,at the moment I am customising oscommerce sites that I then sell on a membership site, when the customer buys a website I then have to upload the sites myself using the oscommerce installer,what I would like is for customers to chose a website and setup themselves using a one click installer were they do not have to upload any files or get involved with MySQL,just put in there web address [login to view URL] need the script to allow me to add new websites as I make the and make them available to my customers,would need to see the script works before payment. Many Thanks Regards Steve.