Kamailio Expert need

We need kamilio expert who can help to conf and document his work. So we would like to have one/two kamailio proxies for all our customers. We would then use kamailio to register server where we check from-domain, check againts srv records or similar to know what media (asterisk 1.8) to send them to. We will have huge table for sip users that are accessable from kamailio and will add user via API from all customers installations. We would also for it to help with NAT and logging of calls originating and terminating so we can logg the event for reports. It should be able to handle load balancing for specific customers, got a rather huge one incomming that will need multiple asterisk servers.