Asterisk installation and maintenance.

Hi, I would like to setup an asterisk system for our shared space rental project. The system would serve the businesses renting spaces and the team. We have room for up to 150 extensions. The config of the system should hold the following points: - Connection to a partial PRI line or remote sip trunking or voip providers The equipment we will use is yealink t22 and 28 - We would need an IVR and a calling program set. - All voip phones would be ip restricted. - Call billing in min intervals. - Call recording. - Conferencing. - Fax to mail . - Video calls (pls elaborate the infrastructure needed). - Redundant server. - Instant messaging in groups. - Voice mail box. -The PBX would be a hosted one, in a data center. - Sofphones. The project will be done in Israel. Let me know if you need any more info. Pls share the pricing scheme for the above mentioned project. Thanks, Nick