If i use the lean model and test my MVP with limited number of customers (suppliers) available for my user (buyer) to choose from wouldn't it result in creating a bad user experience as they will not find what they are looking for?
You should wait! You need to do market testing with real buyers that would have a real application for your site. If you roll out prematurely and do not provide a positive experience, it will be costly.
Offer your service for free for a limited number of potential buyers in exchange for their feedback. They become your beta testers. It does not have to be free forever. Let them know at some point the beta project might be over.
I am offering free calls to first time callers. Use this link to schedule and we'll talk more in detail about doing this the right way.
https://clarity.fm/kevinmccarthy/FreeConsult