My favorite tube in the 6DJ8 family is the Telefuken E188CC.
It is very detailed and laid-back (if this is the sound you are looking for). Siemens CCAs has more bass, and Valvo E188CCs is detailed but a bit forward. Amperex made many differnt types ranging from 6DJ8,6922,7308 Bugle Boys,PQ,USN,CEP,Gold Pin,World Globe,pinched tubes,made in USA, Hollad A getter& D getters (BTW D getter tubes are mellow sounding tubes)
Anyway, all this is quite maddening. I agree with Wlutke, these tubes can get very expensive, and Ebay is a good source to obtain some of these tubes for a listen. Good Luck!