If you can build an electronics kit, you can build a bottlehead.
I'm not familiar with Heybrrok speakers so I don't know if the kits would work well with them. Most 2A3 or 300B based tube amps are easily accomplished if you have the patience to read instructions and can put together a simple electronics kit. I've built two of the Bottlehead kits and I am pleased with their results. Bottlehead has a surprisingly deep knowleadgebase and a large community of active people who can assist you with your questions and problems. (Even at 2:00am in the morning!)
I've never built the Bottlehead amps because they do not produce the amperage necessary to drive my ineffecient speakers of choice. However, with a good efficient speaker set, they will produce some pleasing sound. (92+db efficiency)