Its looking like we will have to go this route due to performance, storage and availability requirements.
We have 2x sites with servers/data, (HQ and DR).
HQ is running 2x HP proliant dl 380 g7 servers with 3tb of data, running c6-8 vms. We backup to NAS and replicate between the hosts using acronis. We are also still using tape for exchange.
DR is running a single host with live VMs ready to go in the event of a disaster. We replicate databases and documents here.
To install a new HP server at site DR, with more ram, storage etc and move the VMs from the old host to new.
Pull the old server and install it at HQ.
Install new SAN, iSCSI i expect, HP or Dell i guess (not looked into is much)
Upgrade the vmware licensing from essentials to standard/enterprise and replace acronis with veeam.
Use the old server from DR and hook up to new SAN at HQ, migrate the VMs across from 2x servers to SAN,
Use the 2x old servers as additional hosts and deploy HA, FT, vmotion...