HSRP between DCs

Howdy,

I am trying to get an understanding of the best (most common, best practice) way to accomplish this. We want to have an internal core Router1 (C9500) at a DC1 and an internal core Router2 (4500-X) at DC2. They will share certain interface VLANs using HSRP (which is not setup yet). These HSRP'd VLANs would primarily be for the virtualization network. Currently these routers are using EIGRP to communicate with each other via an etherchannel bundle.

Since we use EIGRP to route between these two cores, I would assume that across these same physical links that we would need to L2 span these HSRP VLANs. Is this all that we would have to do to get this working?

The main goal is to be able to swing VMs between each DC without having to re-ip the VM.

Could someone please shed some light on this topic for me?