Real Estate using Multisite

Does anyone know of a way to use WordPress to setup a situation where by there is a master site (head office) that is used to generate agent sites as separate domains.

I have been looking at a lot of themes and plugins but can’t seem to find anything.

My main requirements are:

1. A main site (head office) with sub sites (agent sites)
2. Allows separate listings and a separate blog on each agent site.
3. A front end editor for adding listings and blogs.
4. Must be responsive

I have seen a lot of commercial offering where by you can pay a monthly fee per agent but I was hoping to implement my own WordPress solution.

I am an investor and I want to provide all my sales people with their own brand but at the same time leverage the company brand.