Copy Clone Website

I have an existing mysql, php driven, online dating community, hosted at one domain.. I want to clone the original site, by copying and modifiying as needed all of its existing scripts to a new domain. The new domain will host its own copies of the scripts, have its own ssl for order processing, and have its own instant messaging system. I want to use only ONE database, the one still hosted at the original domain, for both the original and clone websites. Columns site_id=1, or site_id = 2, have already been added to the tables of this database, to allow this to become a common database shared by both the original domain and the clone. It will be a common database but members records and general domain specific settings will be defined according to site_id. Ie a member may join both websites, and would have two unique data records, one for site_id = 1 and a second with site_id = 2. General settngs such as prices, terms, etc, should reflect site_id, so that we can offer different prices etc based on website. After copying of files, the settings "includes" should be modified to identify the clone as site_id=2, for accesses to the common database. The contractor does not have to work on cosmetics, as we have already defined new css stylesheets. The original administrative scripts hosted at the original domain, should be used for both domains. However should be modified to indicate which site_id is being worked on when admin approves members, or modifies the data for templates. When admin manually approves a member an email is sent to him. "Welcome to our site". This function needs be modified so that emails sent reflect the correct site_id. Similarly other emails automatically generated by admin, "Thanks for registering", "You will expire soon", "You have expired", "You have a message", "You have a Say Hi" which are sent out should reflect the correct site_id.