I'm probably going to try some Electro-Harmonix tubes, but maybe TJ's or Sovteks or something else. But I love the cool blue glow of the inexpensive Valve Arts that come with the kit, and they sound good too when they don't click.

One of my Valve Art 2A3's clicks, and the problem is definitely in the tube - Symptoms follow the tube when swapped between amps. And the feedback I've gotten from others is that this is a common symptom that appears in about 50% of the Valve Art 2A3 tubes sampled(!) I wish that weren't the case 'cause I like their sound and love that blue glow.