Advanced Docker Networking Consult

We're trying to build what's ostensibly an IPv6 anonymizer service that will allow connecting machines to use a gigantic pool of IPv6 IPs and will provide decent anonymity to the connecting computers. Where we need some insight is this: We want each container to use its own IPv6 IP--or even a pool of IPs--for its outbound connections rather than relying on the host machines' IPs. At random points each container will then dump its IPv6 IP[s] and get another assigned from the master pool. Here's the rub: What we're doing now always uses the host machines' IPs, which am no bueno. I've seen a couple of conflicting opinions on the best way to make the containers use their OWN IPs, namely using some fanciness with iptables or Docker's IPvlan. So, rather than us spending a day or more spinning our wheels on the right way to execute this, what would you do? iptables? IPvlan? Something else? So, first thing we'd like to do is speak with you one-on-one and see what your thoughts are. Let's figure out what the right way to go is and what you expect the project to cost were you to take it on. This is posted as a "Simple project" just to get this listed and so we can start discovery with each other and see what's what. Lest it go unsaid deep understanding of Docker networking and IPv6 are a must.