CRM for Realtors

I need a CRM system where all thé communication with employees of the agency and the customer of the agency could he interlinked and communicate through the system. I want to stop the use of multi-platforms that are being used to connect with potential clients and sales team and other employees to eachother.
All the sales, accounts, marketing, and inventory and all the other things should be manage inside CRM.
This could be the product of any company, I’ll prefer to have ready made demo of the product.
Preferred language is php codeigniter.