Network of Multisites

I am on a mission to create a network of multisites. The reason being, is that we host many client sites and are slowly moving our clients to WordPress. My idea is to create a Multisite for 20-30 sites on a single Dedicated IP and then link the networks together with a single interface that we can us to manage all the sites. I know there will be a good bit of programing involved, which I am fine with. I just wanted to see if anyone has an experience with anything like this or could point to any reference material. I would prefer not to re-invent the wheel. The main reason behind limiting the sites to 20-30 per IP is that many of our clients have similar sites and I think that Google might have an issue if we end up with 200 similar sites on a single IP.

Thanks,
JR