Build a website - repost

To add more clarification and hopefully it'll help my designers in understanding the real concept B2B marketplace for businesses looking for overseas partners (upstream manufacturers or downstream distributors) I'm looking for a website similar to Amazon or even Freelancer, where different companies can show their company profiles and different products. Clients can also publish their requirements. Pricing and other sensitive data can be communicated through private messages. To give you more details on the job - Physical products will be sold via the website. However given this is a website to facilitate overseas cooperation, I will include shipping/logistic companies, specialised custom clearing agents, legal experts, accountants etc as my corporate partners. I.e. create a one-stop shop for clients as cross-border transactions require much more thoughts than doing local online trades. Therefore I'll need those corporate partners can also register/log in to my website. Also the platform will be managed by sub-users, companies and corporate partners can manage their specific/assigned areas. Hope the above helps. However, as the company is still at its early stage, so business model may change in the future according to client requirements, therefore I'd like to have a website which offers the bare minimum functionality which will be flexible enough to adapt future changes. Pls feel free to leverage on your prior experience and suggest on any solutions based on my above description. Thanks and regards, Irene