Build a Website

Hi I need a developer to build a social media platform for me. this social media should includes three different services, include a profile (single sign on), chat module and a web module which some gamification elements perform in it. I build one before with my developer, but he is leaving for a better job and I want to see if possible to create one from scratch, by using the prior experience. of course the website is simple and easy. I broken it up to three different services just for future. profile service includes the basic elements of any social media (basics + photos). chat service includes a chat module with additional elements. gamification service includes the basics of point, badge, exp system. As I told I have prior experience of such website, so am able to manage things and exactly know what I want. So, look forward to know your propositions which includes the exact phasing of project, the prices, and technical details.