I know it's a lot of work, but there's also the option to take your server elsewhere, to a service, that offers a whole subnet. I wouldn't even think of IPv6-nat as well. Many devices probably won't even be able to work that way. At least you'd be the one controlling the port forwardings, so you wouldn't have to worry that much about your monitoring equipment.
And no, SixXS is/was the only service with ayiya.