Mike, my thoughts on what would make a serious venture...
Bring 3-4 individuals together who share the same basic vision. Hopefully, they would have the ability to purchase at least 80 suitable acres. (Timber, Soil, Water, etc.)
Develop operating principals and governance. If possible, build a lodge where members can stay while working on the community infrastructure and dwellings.
Open it up to 20 "Founders" who pay $30M each for membership. This would be your core operating membership and initial workforce. Growing from there into food production, energy systems, compatible industries for income, etc.
Additional memberships, internships, conferences and lectures, various media productions and other educations formats would follow.
Use the Campus as a model, incubator and finance stream for starting others throughout the U.S.
Here is a link to one of many systems that would be an incredible asset to any ecovillage...
http://www.algaeaqua.com/AACT/GPH.html