Setup of asterisk servers with redundancy and call distribution

NOTICE that you with you bid must deliver a detailed description of how you will solve the task and which software it includes, and why this solution will work (preferably with a link, that supports this claim). Today we have one active PBX server, which receives around 500-1000 calls per day through 200 DIDs. As we within the next few months expect to upscale our business, so we daily will receive up to 5000 calls, then we want a more stable setup. We want to have our servers distributed on two locations, which are Germany and France, the servers both have a public IP. When both servers are active, then the idea is that they must divide the calls between them, so that we avoid overloading the servers, if one goes down, then the other must take over 100% automatically until the server which what down is back up, whereafter they atutomatically must to back to distributing the calls between them. The task is including all of the work such as installation of servers, purchase of necessary licenses, transferring data from current servers and testing the setup. The bid price MUST be including EVERY expence including the prices of the required licenses.