Build an online API portal to add/update product, using a file upload

There are 2 parts to this project. Part 1 is our primary focus. Part 2 is our secondary focus. Part 1 has two sub parts; (a)eBay and (b)Amazon API integration's. (1)We need an online cloud based solution that allows us to add, update and remove product from (a)eBay and (b)Amazon. (2)This solution also needs a mapping portal, that allows us to map different file formats based on different header names and layouts. (1) Functionality - overall points: We would build product on a .csv file, and upload this into the cloud based solution. This tool would then update any existing items on eBay and Amazon and add new product also. The csv sample file can be provided. Variation data and parent/child groups must have a Child SKU stored per row. Variation data and child SKU's are therefor grouped by a Parent identifier, but are each on new rows. We would need to be able to specify in the file which product are sent to which marketplace, as there would not be the same required listings for each. For eBay, the SKU must be used to map and update product which is called the custom label on eBay. The same SKU is stored on Amazon as the identifier. Stock controls need to be both numeric values and/or true/false values (where 10-100 could be written where true, and 0 written where false). We need to be able to choose differently between SKU's. (2) The mapping portal but be a simple definition table, which allows us to define different mapping templates depending on file. Example, File A may have headers: title, size, price. We would be able to quickly define the file to Map to template A, where these header names are used to upload product. File B may have headers Productitle,productsize,productprice. We would need to be able to add a new mapping template B to define these headers too. Multple mapping templates will be needed. We would like price breakdowns on parts (1) and (2), along with extra price breakdowns on (1)a and (1)b. Candidates producing a competitive but accurate quote will be contacted for a call on Skype to go through in more detail.