http://www.miraclesoutofnowhere.com/
Preorder
About the film:
In 1973, six guys in a local band from America's heartland began a journey that surpassed even their own wildest expectations, by achieving worldwide superstardom... watch the story unfold as the incredible story of the band KANSAS is told for the first time in the DVD Miracles Out of Nowhere.
This actually looks pretty good. Some of the interviews: Brian May and Garth Brooks?
I'd go for seeing this in a theater, but odds don't seem likely with the DVD release it won't.
I doubt there will be a ton about the original or what was called "Proto-Kaw" period, but maybe in the bonus footage?