Multi Site Magento Based System Serving 18 Websites

A magento based system is required to power 18 different sites within the beds and mattresses market ( see worldstores/ bedroomworld to see what we are trying to achieve)- 2 primaries showing the whole range and 16 sub sites showing only one specific category. ( so each product or category will be only shown 3 times in total). each site is to have unique static content, category content, and product content. will interface with paypal web payments pro (or sagepay) as well as paypal express and google checkout. some complicated product options will need to be taken into account. css for all sites will be very similar and needs to be designed based on some basic guidelines- all sites to look almost identical- easily identifiable as a single brand- we are trying to create a brand feel to the group. permission based access will be required by sales staff, admin staff, etc, as will single point order/sales management. must integrate with sage line 50 ( end of week reconcilliation is fine). if this project is successful- i have many other projects for the right person/ group ***This system is to run from a single hub*** It will have to auto generate confirmation emails to customers and and also despatch emails. it will give the ability to send out a mailshot - from a dedicated and changeable email address- this will be a promotional email designed by our staff and must be changeable by us. must have analytics integrated, please take into account that i will require the admin section of the back end, and options ( such as categories and products) will need to be customised to make it easier for admin staff to upload new products. EACH PRODUCT WILL ONLY BE INPUT ONCE. please do read this ad before replying- please starty te reply by saying you HAVE READ THIS BRIEF also, please ask any other questions you may have. No silly prices, No timewasters who will not finish the project, just quality freelancers who want to develop a working relationship with a firm who can give constant work. thanks