I have used quite a few new tube brands in the 6L6GC category. For the Two Stroke, I just used new JJ tubes. I havent dived too much into NOS yet, aside from dabbling with the 12AX7 and Rectifier. I have a couple NOS 6V6’s to try at some time, but…. time and all that.
In terms of the 6L6’s, In another amp project, I have used Sovtek, Tube Amp Doctor, JJ, and Winged C. For that particular amp, I really liked the TAD tubes the best.