I need a front and back office solution

Hello, I need a front and back office solution.
1. FRONT OFFICE - I need to market to individuals for my Streaming service, where they can sign up and pay for service.
2. Once they sign up, they can control their site and theme with the back office.

I would like to use fixer for the Front office and Live Theme for the back office theme that they (the Clients) will be controlling