Build a Lead Management System for Real Estate Consulting Company with multiple API Integrations

Build a lead management system for a real estate consulting company to be accessed by individual sales agents and their managers with various API integrations for call management, lead capturing (google ads, facebook lead forms etc), google calender integration, followup management, email and whatsapp integration etc. Following are the critical elements to be considered while building the LMS - 1. Dashlet Feature: The interface has to be very clean with the ability for the admin to customize the dashboard using widgets as dashlets as per user category (sales agent, manager, marketing head etc). 2. Ability to generate multiple types of reports depending on the type of function (sales performance report, calls report, lead status report etc) We have a brief presentation with screenshots ready for the final product desired which I can share one to one. I also have a few well known CRM for references that I would like to disclose in person so as to understand the design expectations clearly. Looking to work with someone who has previous experience of developing a CRM.