There they have multiple outside addresses mapped to one inside address. They don't specify ports there, do you only want to open up for port 80 or for other ports as well? That should at least give you an idea what is possible. Maybe it is possible to combine it with ports as well.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...