Hyper-v cluster

Hi ,

We have cluster 2012 SP1 has 6 nodes , we have an idea to implement another cluster 2012 R2

We do this due to the following points

• Distribute VMs (have the same function like exchange front end servers) on two cluster to provide redundancy.
• the new cluster will be  windows  server 2012 R2
• We will assign storage on the new cluster from different SAN

1. Can you share me with your comments  about it.
2. is it applicable to move VMs Back from 2012 R2 to 2012 SP1.
3. what is best practice to implement this idea ?

thanks

Ramy