Hello Alex, I made a project like this before. Please check at my portfolio, I created a CRM for real estate, is something like you need, it has most of the modules that you need, a dashboard, a search for clients, diferent kind of users, agents, brokers, liners verifiers, admin, it has reports, tasks, notifications, historial and so. If you are interested on see more screenshots or an live demo please let me know.
Cheers