Replication with FileStream
Although replication may not be High Availability in design, it depends on your definition of HA.  Certainly it has been used for HA by many people. 

If replication is down long enough it can be marked as Inactive.  To automatically reactivate a replication, you could try using Kin's response: SQL Server replication subscriptions marked as inactive

This runs a job that periodically checks the status of replication and reactivates it.