Are you looking to manage entire presales and sales process within WHMCS?
WHMCS CRM by WHMCSTECH is reached feature CRM, You will be able to create leads, Set followups, Convert leads to client from CRM interface. We felt this was a much needed addon for WHMCS and allows you to host this on your own server so a third party company doesn't have access to your sales records!
WHMCS CRM module is the simplest CRM module ever. Its provide you ability to add calls set follow-ups date and time add product to each call and monitor them very easily. There is also feature to manage multiple branch and ability to set branch manager. Furthermore, The Sales admin can see their client and call reports. However, the branch manager can see all reports for the branch and super admin can see all the reports.