I'm currently running some vintage Bugle Boy 6922's, vintage Sylvania JAN 6SN7's and a set of E.H. 6CA7s, (biased at 40mA). This is my favorite combo so far for my Vienna Acoustic speakers.
With the above combo and a set of Sovtec 6922's it can be a bit too edgy on the top end at higher volumes. The Bugle Boys take a bit of that edge off.
Before the 6CA7's, I ran a new set of JJ KT77's (biased at 40mA) which are similar, but not quite as much decay in cymbal strikes.
I have also run a set of Ruby 6550's but they were just too soft up top. I guess if I had a bright speaker, they might be better, but not for me.
Hopefully that helps.