How to setup remote datacenter wordpress failover?

I am trying to setup a wordpress blog network with 99.9% uptime. My experience with hosting companies is that there are hardware and network failures that can cause significant amount of downtime. So I was thinking of creating a remote failover solution. Is it possible?

I have been searching for a remote (vps in Japan and US) datacenter wordpress (application and mysql database) failover solution, but cannot find anything on the web. Ideally, the solution should be syncing both datacenters at the same time. If server A goes down, then server B will startup. Once server A is up again, server B will send its updates to server A and server A will resume. Since this will probably taxing on server A, server B might have to be 4-8 hours delayed. It is not ideal, but I have not found a solution to keep them in sync constantly.

I have searched under failover, clustering, replication, mirroring, syncing, and high availability over search engines and forums, but have not found a robust solution. I have read about dns failovers, but many have recommended that it is not a good solution.

If you have experience with a remote datacenter wordpress failover solution, please share.

Thank you.