An Ubuntu Live CD behind NAT in a VirtualBox virtual machine with miredo tunneling installed so IPv6 would be activated is all you need to get up running with an external IPv6 at your premises. Placing it behind NAT keeps it from receiving route advertisements from the main network so your IPv6 client wont be on your main IPv6 network.
Boot the virtual machine and ensure a Teredo type tunnel is installed. For Ubuntu, sudo apt-get miredo does the trick. There are clients for other operating systems and GoGo6 is one of the more popular choices.
You now have an external network that you can use while at home without needing to leave your premises.
Configuration steps from NAT to test are shown below along with logs showing access and denial of the external client.