Joomla 3 SobiPro "add on" development / customization

We are looking to develop an add on that works with SobiPro directory for Joomla3. The directory as we know it, lists companies by categories of business, on a subscription basis. What we need to add is : Each company can add products that get listed underneath. Technically: Create a new table that captures products details and images for a company. Edit existing Listing Form to have the ability to "add products" A new screen should open to capture multiple products, with joomla features (save, copy, publish, image Gallery, price, etc ...) IMP: ***a proof of concept will be required before hiring. So please if you are not capable, do not BID. We know exactly what we want.