Web site for a new buying group

We need a website for a new bulk buying group and need the following features 1. CMS system that allows you to create and edit a page, once you create a new page it should automatically use the websites own template, allow you to post information on a product and contact details (similar to classified ad website but we will have a single page for a product such as Iphone and it may have 20 suppliers prices and contact details) 2. allow a user to register for membership, take them to payment stage through our merchant account, once the payment is complete a new unique user number will be generated and user will be emailed login. For every new user, a dedicated list of suppliers (20-30) will be emailed the users details inc user account number so they can add them to thier systems also. We will add the emails to suppliers 3. Allow us to suspend a user account, once we suspend an account, the same list of suppliers will be emailed to be told the user has been suspended and will contain all user details. 5. Allow new suppliers to register and post products (they will be allowed to add products but must have limited powers, i.e not be able to delete other user products etc) 6. A message board and contact book to allow members to post skills, wanted work or work offered. This is a new site idea so if you have any ideas that may improve our system we will like to hear them. The work on the site will start in 16-20 weeks once our merchant services are finalised.