Assign one of your 16 addresses to vmbr0 (e.g xxx.xxx.105.111) and set the gateway there as well xxx.xxx.105.65 and bridge to an active port
Create your vm or container, define a network adaptor on vmbr0, assign another public IP (e.g xxx.xxx.105.112) and use the default public gateway xxx.xxx.105.65
However, this is very risky and not recommended. You also should not publish your full public IP addresses in a public forum like this as this is like telling a criminal where you live. Instead, use partial addresses like xxx.xxx.xxx.65/26 where you need to describe or discuss a networking problem.
Personally, I would sacrifice one of my public IP's to a VM running a firewall - e.g pfSense, and then I would NAT public IP to private IP through this firewall for greater security and control.
