Yeah, I agree, they did support and befriend a few of the hipper acts and Head gave them as much retrospective artistic credibility as it did destroy their career at the time. As We Go Along features Neil Young also and Can You Dig It? has another Buffalo Springfield member (Dewey Martin) on drums. Unfortunately none of the available compilations seem to do justice to their more unusual or contemporary endeavors so it may be a case of downloading individual tracks - all the albums I mentioned are available as downloads on Amazon so you could probably spend about £10 and get 10-15 of the essential tunes for your taste.
I also forgot to recommend Circle Sky from the Head soundtrack but go for the bonus track 'live version'!