Classified/shopping cart website

Need a Web Site designed that will function as a combo Classified site and Shopping Cart site. Something similar to Big Commerce with content management control yet also offer Classified Ad postings by customers. I anticipate 4 areas of the store: New, Used, Classified/Consigned and Damaged New, all with several sub category options. There will be 3 levels of users offering varying rights of access. Site administrator (full permission to post all areas of store and to use Content management interface to manage database/site and page content), Consignee Customer (access to post to consignment area only), Consignee Retail (access to post to Consignment area or Damaged New area). I would like the database/site to be scalable, reusable and be a CMS. SEO is ultimately important to the site. I would like the database/site to stand alone and be able to utilize any combination of the four areas of the store at any given time. I may just use New and Design or maybe just Consignment/classifieds. Here's more detail: 1. NEW items which will be paid for via secure shopping cart. Shipping options would be predesignated for each item in advance. The choice as administrator of the item would be: local delivery (fee), Pickup only, Canada post delivery (fee), etc. The choice of delivery options available would vary by item. 2. On USED Items (which I may inventory at a physical location), I would like the ability to be able to apply a % Deposit on some items in order to hold for customer until pick up. Again, I would like the option to assign predesignated shipping details. 3. DESIGN CONSULTATION services to be booked and paid for via shopping cart. This system area needs to offer an opportunity for customer to choose their time, date and subject location of their consultation request. It must be able to match to my time table of open availability for them to cross reference at time of booking. I would need to get an email notice that there is a request or booking with payment has occurred. For now, my consult locations will only be offered locally; Midland, Penetang, Orillia, Barrie, Wasaga Beach, Collingwood, Port McNicoll, Victoria Harbour, Tiny & Tay Township and Cottage Country locations. I imagine that the person requesting the consult will also be able to identify location of consult via google map or postal code? I would require categories of consultations for customer to choose (ie: paint consultation, design consult) with corresponding price field, etc so essentially a drop down box of type of consultation, corresponding price and description field. 4. CONSIGNMENT items to which I will not be selling the product direct, the buyer and seller will communicate all essentials of the product description, delivery, location viewing, contact, pictures etc. I will be charging the consignee a fee for posting their product details/photos to my site. The charge will be based on a % of what they will be asking for their product. That amount is paid to me via checkout. I envision that they can completely go through the process, loading all their info but not able to upload/process until paid at check out. After product is posted, I have nothing to do with how the product is communicated (although I do not want them to be able to put in obscene comments, pictures etc, so a filter would be needed). Once a person has posted their own consignment item I want them emailed a confirmation of the same. Also need user consignment items to be automatically removed after a specified time period. Essentially the Consignment area acts as a Classified ad area. 5. NEW BUT DAMAGED items can be entered by into system like consignment items but only by designated user. 6. I am not sure what I need to consider here. Any advice on affiliates? 7. Allow administrator space to advertise for and post select outside advertising.