ASTERISK IPPBX EXPERT

We ae looking for an expert in advanced IP PBX systems in order to develop a quality and innovative business telephony solution that offers international phone management services for business users. We need a IPBX system with key features such as custom-built IVR, messaging, billing.,..Technology used would include Asterisk, A2billing, IVR, DID routing. We need also to set up a customer online panel to manage user voice profile, call forwarding, billing and invoicing, payment, acess to special services to be detailed in PM (mostly based on helping customer manage multilingual inbound sales messages) professioanal should also have exprience in using plateforms such as didx to acquire and configure SIP numbers. The project should include development of the whole system + web panel and on-going support for 12 months. We expect the project to require less than 30 days for first version. Please post existing examples and references of voice or telephony services. Do not bid if no or little experience in advanced IP pbx services. Full details on PM after references submitted