Hello Dear, I've read your project description and I can make changes into multivendor website including ingenerate payment gateway, design pages, vendor side, order page, currency counter and much more in an organizational manner as per your requirements. Let's have a quick discussion about the project.
We have extensive experience in designing and developing Portals, Web and Mobile application, E-commerce in all major platforms, etc.
I am sharing our portfolio with you have a look,
https://www.freelancer.com/u/kamran2012
Thanks,
kamran