Hi Paul,
Congratulations on reaching the threshold of setting something significant up.
To add to Glynn's post about references to other community models, it would be worth looking into (if you don't know about it in detail already) Kotare village in New Zealand - set up by Kay Baxter and Bob Corker. I had a visit there last year and while it's still in it's infancy and it's still imperfect, they have a very good model in place I think - especially on the economic and social side of things - all important when setting up a community. Almost every 'eco-village' or 'alternative community' ever set up has either broken down or failed to live up to it's dream due to poor design. Only time will tell if Kotare will succeed but Geoff Lawton was saying they have thought long and hard about how to structure it (knowing well what has been the downfall of other communities) and have most certainly gotten it off to a good start. I was impressed by the "how do we design a local economy that is sustainable?" bit of it particularly. Perhaps you are already well versed in what they are up to, but if not it's worth checking out.
http://www.koanga.org.nz/kotare-village /
http://communitylandtrusts.org
On a slightly separate point, I am curious to know if you've already designed the landscape? The large scale water harvesting, zonings etc. Is there a (to borrow Geoff's term) 'mainframe' design worked out already?