E-commerce comunicative with other sites

I would like to create a website platform that brings together online offers retailers from different online shop, where it would be possible to search products on the basis of a specific description (e.g. fixed camera barrel of 50mm) and which it would be also possible to refine the search according to specific criteria (size, color, brand, material, price, etc…...). See as an example: [login to view URL] or Amazon.com. The key difference of my platform from others (see example before) is due to the option granted to each customer to buy different products from different online stores, directly from their website and make the checkout only with an account number from my platform (avoiding to make more checkouts from the different retailer website). Afterwards, each retailer will receive customer data and orders details. Everything will be processed directly by the retailers. Invoicing, delivery and administration of customer’s orders is under responsibility of the retailer/online shops. It is important that once customers complete his overall order from our platform, orders must be sent automatically to each single company for processing. Each online shop (retailer) who sign an agreement with my web platform, will pay a percentage based on the monthly sale made throughout my website (calculation will consider returns and discounts). As an example, the overall order must specify sale condition of each retailer (individually). For example, if a customer buys 3 products from 2 different retailers, the summary basket for each customer is as follows: Recap Retailer 1 Article 1 US 100.- Article 2 US 200.- Shipping costs US 7.50 Delivery on (oppure timeframe): xxx Sales condition: xxx Recap Retailer 2 Article 3 US 50.- Frais de livraison US 0.00 Delivery on (oppure timeframe): xxx Sales condition: xxx TOTAL CHF 357.50 I would like to have as well an interface to manage locally this site. Based on the above description, please answer this questions (the job will be gave to the freelancer who give the best answers: How is possible to gather information products (description, picture, characteristics, conditions ecc)? It's importante to input automatically information on my site as the data are already available? How is possible to retransfer order to the online shops (retailers) in order that they can process them ? Which possibility I have to secure customer’s data (particularly payments information) ? How is possible to obtain information of sales made by each online shop throughout my site on a regular basis (including returns and discount) and how can I charge the online shop individually (on the basis of each agreement signed with each online shop (which can be different from on online shop to other)) ? I need of course of the mobile app, the comunication with social media, an emailing list and the possibility to change the first page on basis of promotions. The design should be sober and professional (see [login to view URL]) In order for me to choose a freelancer (as the offer is very high) please let me know how many hours do you need to complete this work and the total amount you require. Thank you.