I have understand your project that what you are wanting from us. I have made many e-commerce websites on freelance with my partner.
I'll complete this project using HTML, CSS, CSS3, Bootstrap, Java Script, Jquery, Ajax, XML, PHP and SQL.
Admin side and website user sides both will be responsive to open in any device (mobile phone, tablet Pc or every kind of laptop or computer).
I will make sign up, login and chat system in the website. Website will be user friendly and eye catching. If you agreed to assign this project to me I will show you my work by screen sharing or by sending snapshots of my projects.
Thanks for reading my proposal.