A2 Billing+Camailio+Asterisk Server setup

I'm looking for someone to remotely setup the above infrastructure . In particular someone experienced with commercial setup and security hardening of VOIP servers. Below are details of setup: Project Description 1. Install Scalable Voip Platform Including Asterisk, a Sip Router a Billing System. 2. The installation will be on 2 VPS. Options include (Linode, Amazon EC, Digital Ocean, etc.) 3. Users can select and pay for DIDs online. DID selection could be by Country, Area Code, City Code or Country and State.. 4. The System will handle Prepaid Calling Cards allowing them to top op their accounts for DID usage and termination services. 5. Use Sip Router (Kamailio, Openser, Opensips) Load Balancing, Registrar, Routing outgoing calls by LCR for termination 6. Integrate a billing system (A2Billing or suggest other). If A2 Billing, code for email dunning or ability to download counts receivable (late payments) to an email platform with Dunning capabilities. Ideally, I would prefer to add dunning to A2 Billing. 7. Allow scalability 8. Integrate with CRM(Vtiger, SugarCRM or Other CRM of choice. Im open to your suggestions of other opensource packages) 9. Integrate with Mailchimp([login to view URL]) server 10. Sip Routers (Kamailio, Openser or OpenSips ) Split for incoming and outgoing calls 11. Asterisk Realtime (4 instances) 12. MySQL Database (Master/Slave) 13. System Testing Tools( your choice) 14. Security Tools(Your choice)