Create new eshop (with magento)

Create new e-shop with magento. - create sorting, - create categories, - auto-update stock every 4 hours (from external xml file, which is not compatibile with magento), - auto-update products with all attributes once a week (from external xml file, which is not compatibile with magento). Install new version magento on our virtual server, create adds-on for updating products and stock, setup cron for adds-on, create basic design of eshop and create basic structure and categories for products. Sorting products have to be more logically - e.g. we have in database 50 t-shirs - we want to have only 1 t-shirt on eshop with 50 attributes (based on sizes, colors, etc.) Petr Jasak