vCenter position

Hello,

today we decided to switch to HA, then double servers and vcenter for control.

I doubt, the vcenter appliance is better to keep it inside a host that will be driven by vcenter itself or is it right to put it out of the HA environment and any cluster?

Cluster1 [host + host] + external vcenter

or

Cluster1 [host + host(with vcenter vm)]

Thanks