Callcenter/CRM system

we are a small callcenter/marketing agency. we specialise in making introduction calls and appointments for other companies. we need a webbased application for automating and handling our calls. We have something similar in PHP now but it's architecture is wrong so a new application must be built. A job description is attached. We expect that coder will install the application on our server (turnkey), and will guarantee support for at least 6 months after delivery of the application. We expect a modern and user friendly design. We do not want to limit this project to PHP/mysql. If you have a better solution, that is fine !