We support load balancing configuration. In reality, this means that we can run multiple servers with shared database and content, with a load balancing front end. We do however not supply the front end, as that can either be made with special hardware or just another PC running an simple nginx configuration.
The database can be clustered as well, but for that we recommend running the database on Linux/Unix and we or a database specialist can help with configuration of a shared solution.
The content can also be shared and using an high availability storage solution you can make sure that the content is available.