I have an experience of 1.5 years working as eBay Customer Support Executive and hence I am aware about eBay and PayPal functionalities in and out. Please feel free to contact me to discuss this further.
We are iWeblane Softwares, We have read your project description and can see the requirements. We can help with Paypal and eBay selling online. Please come on FL chat so that we can discuss it more.