clone squarespace.com w/addes features

i want something really close to [login to view URL] with some added features.(a clone) below are the added features or modules: email system / users should have access to webmail page. shopping cart addon / users should be able to plug in a shopping cart system in their blog using either paypal or any other major cc accepting payment system. (domain mapping should be available to blogs for users who want their own domain name) need project complete by end of year. (i should have a administration page for overall control of the blog system and signed up users) note: use any major payment system to accept cc for online signup/memberships. i will provide all text, images, backgrounds, etc content.