Asterisk VoIP Call Centre Configuration

We are looking for someone to configure an Asterisk server for our company. I have outlined what we need below. Hosting: - We will install linux (preferably Debian) on a server in our rack, and ensure that it has network connectivity - Asterisk needs to be installed and configured on it. Brief details on the dial plan are below. External interfaces: - Outbound calls to be handed off via a SIP trunk - Inbound calls to be received via SIP, i.e. the external switch will end a SIP call to a specific extension on this new server Call routing: - 5 extensions will go straight into queues (first available agent, 20 second maximum wait before going to voicemail). - 1 extension will present a single-level IVR, which will then route to the correct queue Agents: - Agents will use SIP phones (we already have these) which will register with Asterisk Nice to have, but not essential: - Agents can be linked to more than one queue - Agents can be assigned to different queues via admin web interface - New queues can be added/configured via admin web interface