Build me an intercom communication system -- 2

Looking for an electronic engineering company to create an intercom system using mobile technology (3g~4g). The system should be two way with battery backup for about 4 hours in case of power failure. Over and above the normal two way communication a sms will be sent to different numbers when ever there is call from the system. We should be able to program the numbers to be dialed out and sms to, and change remotely if the need arises.. The system must allow via cables for an external speaker, microphone and button to activate call. There is a 220VAC power [login to view URL] will be enclosed in a reasonably protected case nothing special. The volume of the speaker should be able to be adjusted. The antennae should be external. Your cost should include the supply of two prototypes and all associated costs. The budget price is only for guideline purpose. Prices submitted will be what you are evaluated against. Payment will be made on completion. Please also indicate your lead times from award to prototype.