ZENCART - Create 3rd party seller CMS to allow manage products and orders (PARTLY DONE)

Hello I need experience PHP developer with knowledge of ZenCart. Previous coder done good work but failed to finish the project. I need somebody to take over. I need this work to be done ASAP, consider this urgent. I am looking for the price up to 300$ (2 milestones). Communication and updates is a must, I am hoping to have this done within 10 days. REQUIREMENTS: * Allow 3rd party users = Sellers to register and get access to their account (DONE) * In their account Sellers can upload products, edit products, see sales and stats for their products (DONE) * We need ability to add product / edit product with product attributes. Only 1 product option per product. Product Options are predefined so they can be only selected (dropdown menu) * They can also see breakdown of sales and how much Admin owes them + see statistics of their sales, visits and best to compare it with previous months to see the comparison. * Admin will have page in admin to manage all Sellers and see their sales, stats, details, ability to block them, edit them, remove them. (PARTLY DONE) * Admin will see breakdown of monthly sales including the amount he owes to sellers. * Admin will be able to make a payment from admin to seller just by one button click.... after checkout payment will be recorded and monthly breakdown recalculated. * Admin should be also able to access products by Seller and make changes to them if required * Payment system is Paypal, all payments from website goes to Admin account (normal checkout way) but then he will pay the sellers (after deducting his profit % which is variable and can be changed for the whole system). Admin is going to pay Sellers from the admin where he will has already calculated amounts and by clicking Release Payment it will be sent to seller by Paypal / automatic. The key is to make management as easier as possible for Admin and Sellers. Seller section is external from ZC only connected to the same database. WHAT IS DONE ALREADY: In ZC admin we have already page to show all registered Sellers, we have email alerts working. Most of the Seller management is already working here. Seller section is done in terms of HTML / CSS, registration, login, add / edit products. I need you to create the above functionality HARDEST TASKS ARE: • We have an issue how to make the ordering, order processing and shipping to work if for example one user buys multiple products from multiple sellers who are in different countries. Solution - The checkout process will be single but once its processed it will generate multiple orders depending on how many sellers are included in the order. From then they will be processed as separate orders with their own order number. - Shipping - this is website for Worldwide use so sellers and customers can be anywhere. Each product will have its own Shipping table consist of individual prices for regions we have (6-7 regions, these are set already). Each region will have 2 prices (price per single product order and price for multiple quantities of that product). Example will be provided.