this is definitely the same thing i am working on myself, its inspiring to see you are thinking the same Sully, and to hear of everyones ideas and experiences:)
i have worked on a few farms and just got off one last week..ill be headed out to another next month for the season. although these are for profit and mostly produce farms(they are for farmers markets and Community supported agriculture) the only way to learn about farming, ranching, and living sustainable is to actually do it. I would suggest finding a farm through ATTRA internships, looking up ranches in your area on eatwild.org and inquiring about jobs etc...as well as finding legit communities that focus on sustainability, permaculture and even biodynamic and french intensive practices and farming(and learning as much about these areas in regards to farming and ranching on your own!)....there are a lot of farms dedicated to conservation, and sustainability where you can learn how to live with the land and animals in a mutually beneficial relationship...many quaker farms use native forage for their herds, however the seeds for this grass is rediculously expensive and as michael said earlier, it does require a LOT of acerage to feed herds and unless you have a trust its almost impossible without harming your land, i would suggest also thinking about rehabilitating already pastured land with cover crops(a lot of them are native), the poo from your animals and time as well as learning to hunt...
there are soo many more factors that go into determining the right location, herds, crops, what each individuals idea of sustainability is, its pretty much becomes one life to gain the knowledge and experience and a commitment to hard work to create something that is actually successful, it requires a lot of sacrifice...that said, there is no more fulfilling work of life that to actually be growing and maintaining your own on the most basic of levels.......i love the ideas of more and more communities growing and gaining support and knowledge from each other...its a nice enough dream for me that some day everyone could walk a few miles down the path and trade knowledge and meat! with my neighbor ...i have had this opportunity here in this lifetime and feel really blessed and happy to think its possible