"I am leaning towards the 7308 tubes that frogman pointed out"
Excellent choice, a few years ago I tried at least 10-15 different varieties of 6922’s in a component and that 7308 in addition to one other tube were my favorites. The other one is in the list here, under Siemens, scrolling down, the 2nd E88CC/6922. Writeup states, "Some are RCA labeled."
http://www.audiotubes.com/6dj8.htm
Just a matter of personal preference, I did land my plane with the Siemens, but I would have been happy with either one.