Ecommerce with backend inventory management and Google SEO

Hi There, What I require is a website designed, including any artistic pieces. The website is also to include an ecommerce function with a backend inventory management system for me. The websites main function is to lease out technical devices's such as smart phones and the likes. 1) Users should be able to use a drop down menu to select a device. 2) Users are to be able to select the dates for hire. 3) The encorporated inventory system is to be able to see if the chosen device is available for lease or not on the chosen dates. 4) The inventory system should allow me to add new stock; device, pictures, information and cost, from which clients are to be able to choose from the main website. 5) Once the device and dates have been successfully chosen, the ecommerce system (paypal?) must be able to deduct the minimum rental fee (3days) upfront and then automaticaly deduct the rest of the fee, if longer then 3 days, on a weekly/fortnightly/monthly basis, based on what the client chooses. 6) Once successfull payment is made an ORDER email advising me of the clients name, address, phone, email adress, chosen device, length of rental and total fee is to be emailed to me and updated in the inventory system. 7) A calandar function is to be visible to me highlighting what devices are out and what are available. (Perhaps this would be a secure section of website) 8) Website search engine optimisation is also required (Further information can be discussed for a small marketing campaign)