Making Windows 2012 DC HA with Hyper-V and Exchange 2010

Hello,

We are currently running a Windows 2012 DC with Hyper-V running a Exchange 2013 in a RAID-1 and RAID-10.

I want to add another physical machine, a SAN, and make the DC redundant.  

So, this what I plan on setting up.

Install 2012 on second machine, install HA on current machine, make HA include both machine.  

Add Hyper-V and DC Replica to clustering service.  Store Hyper-V machines on SAN.  

Should we purchase 2012R2 with our current 2012?  

Just looking for feedback and possible answers with current configs.

Thanks.