For vintage tubes, I suggest you google "Joes Tube Lore".
He has tested many different 6922/7308 tubes and has posted his opinion.
It is a good starting point.
Mullard's are more of a softer, euphoric sounding tube and may be to your liking.
You could purchase several pairs of different ones and those that don't meet your needs could be resold at a very minimal loss.
I can't help you with New reissue tubes.
Either way have fun and enjoy the journey.
He has tested many different 6922/7308 tubes and has posted his opinion.
It is a good starting point.
Mullard's are more of a softer, euphoric sounding tube and may be to your liking.
You could purchase several pairs of different ones and those that don't meet your needs could be resold at a very minimal loss.
I can't help you with New reissue tubes.
Either way have fun and enjoy the journey.