Have you looked at Space-Tech on Renfrew and 2nd. He's another "garage" operation that is highly touted. Unfortunately, he's "on vacation" much of the year.
Balanced SET? North Audio
Has anyone heard of North Audio in Canada. They build SET amps that run balanced. They are bacically two single ended amps, one handling the positive and the other the negative signal. He says he owns the patent on this. This is why no one else is doing it. Could this be the ultimate.
www.northaudio.com
www.northaudio.com