Build me a small omni channel marketplace website

I need a developer to set up a site which will handle orders and inventory for ecommerce sellers on multiple marketplaces : 1) Need to integrate API's of 10 marketplaces including magento , shopify , woocommerce , bigcommerce , zencommerce and openkart. 2) Need to integrate the API's of 8 courier partners where the seller can choose which courier to use based on price and ratings 3) Ability to print labels of all the marketplaces by accessing them using their API's 4) Central price and inventory control dashboard. 5) Since it is not possible to upload products through API to the marketplaces, need a universal product upload template and ability to convert and download modified templates for individual marketplaces.