If you want to create Highly available virtual machines then the Hyper-v host servers need to be part of a Failover Cluster. They do not need to be part of the Storage Cluster but they do need:
1) Access to the same shared storage for example a Scaled out file Server (SOFS) or a Cluster Shared Volume (CSV)
2) Be part of the same failover cluster.
so in your example you could keep you SOFS storage cluster and then create a 2 node failover cluster with your two Hyper-V Hosts. scaling out this way will make it easier to scale the two tiers in the future.
This video on Channel 9 talks about hyper-V failover clustering:
https://channel9.msdn.com/Events/Microsoft-Campus-Days/Microsoft-Campus-Days-2013/Windows-Server-2012-R2-Hyper-V-High-Availability-with-Failover-Clustering
Windows Server 2016 has introduced a Hyper Converged model which might not be relevant for you Server 2012 deployment but does make for an interesting read:
https://technet.microsoft.com/en-us/windows-server-docs/storage/storage-spaces/hyper-converged-solution-using-storage-spaces-direct