migrate and upgrade ZCS 7.1.3

[fbzimblet]

We have a client that is using ZCS NE 7.1.3 on Centos 5 on top of VMware ESXi

What is the best way to upgrade to the latest ZCS?

I'm thinking of creating a new Centos 6 VM with storage about the same as current ZCS, then install 7.1.3 on it before rsync /opt/zimbra from Centos 5.

zextras migration suite would be my second option