To address the availability point of your comment, Google's terminology is slightly different to AWS.
On GCP it sounds like you want to have a multi region architecture, not multi-zone (if you want firewalls outside the same data center).
> Resources that live in a zone, such as virtual machine instances or zonal persistent disks, are referred to as zonal resources. Other resources, like static external IP addresses, are regional. Regional resources can be used by any resource in that region, regardless of zone, while zonal resources can only be used by other resources in the same zone.
On GCP it sounds like you want to have a multi region architecture, not multi-zone (if you want firewalls outside the same data center).
> Resources that live in a zone, such as virtual machine instances or zonal persistent disks, are referred to as zonal resources. Other resources, like static external IP addresses, are regional. Regional resources can be used by any resource in that region, regardless of zone, while zonal resources can only be used by other resources in the same zone.
https://cloud.google.com/compute/docs/regions-zones
(No affiliation with Google, just had a similar confusion at one point)