That router will not support the public IP address on the private side, nor will it support multiple public IPs, and one-to-one NAT. If you want to use your public IPs, then you should just not use a ...
So, without getting into a lot of detail, we are looking at a setup whereby two different subnets on a given site each have their own router, but using HSRP, each router can act as a backup path for ...