New to develop a back-end CRM for my website

We are in need to develop a back-end Customer Management portal for a call center being put together. We need this to run on PHP and MySQL. I am the website developer and need to outsource this portion of the project. Must be able to communicate in good English and using google chat. The site [login to view URL] takes in leads from customers and sells those leads to our clients. We are looking to add an expansion to the website for a CRM system. Our clients are generally contractors (home improvements, landscaping, ect) We are looking to do the following • Collect Leads from the Website into a MySQL Database • Have the ability to add and manage users • Add Leads to the Database manually using “Agent” Logins • Manage Agents as Users • Manage Clients Calendars, making certain available to place the leads into. • Have a messaging board system to post messages to Agents or private messaging. Some of the items we will need to have is broken down like this: Client Area • Client Login • Client Profile • Payment System (Optional) • Payment History • Leads Management • Scheduling Admin Area • Client Management • Users Management • Accounting • Access to All Other Areas • Leads Management Agent Area • Client Area Access • Client Management • Customer Order • Customer History • Order Editing • Schedule Editing (For Clients)