VMware has deprecated vCenter Server for Windows, see: Farewell, vCenter Server for Windows - VMware vSphere Blog
Check if the following VMware KB article helps with migration to another vCenter.
So best bet is to install the appliance instead, if I'm reading that correctly?
With the appliance install, would the process be that same? ie, default install and setup with no database transfer?
Also can you migrate from vCenter 6.0 to VCSA 6.0, or do I HAVE to go to 6.5?
The "way" is not the same...... its a Appliance.
The VCSA(vCenter Server Appliance) Installer offer a migration from from your old VCS 6.0 on windows to the VCSA 6.7. It takes all configuration, identity which mean IP,FQHN, certificates and passwords to the new installation. VCSA comes with inbuild vPostgreSQL Database.
At the end of the migration the windows server will shutdown.