You can email the designer Mike Dzurko on Audiocircle.
I was curious enough to look them up. The most recent article appears to have been written 12 years ago. That doesn't make them bad or unworthy of a decent amp they were well liked at the time. The Impedance numbers would permit a variety of moderately powered tube amps to work OK if you diudn't need especially high volumes. I would look into used Prima Luna as a start but the type amps are many in number and style.