Marketplace for service provider

"We are looking for someone to develop a marketplace that provides multiple API integrations with other services and payment gateways. The provisioing of the services to the customers will be automated through Marketplace. Secondly, build a billing system with features of downloading to PDF and sharing through emails.
The design of the markeplace to support hgih availability and, the coding should be free of vulnerabilities and subjected to SSDLC model lifecycle. The project shall have a detailed and well prepared documentations. "