Welcome to the Comunitiy - First yu need to understand there is a difference between HA and DR - in simplest sense HA allows you to recover form a single host failure while DR allows you to recover from a site failure. VMware HA functions ona host level - there is software loaded on each host that monitors and communicates with theother hosts in the HA cluister. When a host or hosts fail in the cluster the VMs that were running on that host are restarted on the remaining hosts. Since the VMs are restarted the physical hosts can be different manufactures, CPUs and memory. The one thing that is required is shared storage - so all the hosts in the HA cluster need to be connected to the same shared storage.
Now if you are looking for true DR where you can recover from an outage at your primary site to a completely different physical site than you will need to look at something like VMware SRM or some other site to site replication -