Almarg,
Ironically, I have this exact same pairing, having bought a VAC Renaissance 70/70 MkIII a month or so ago (in an auction) to try with my Ulysses speakers. I am trying KR 300B tubes, which I literally lucked into finding at a crazy good price. I believe they are a big improvement over the JJ 300Bs that came with the amp (although they sounded quite good as well). I am still messing around with different 6SN7s. My favorite combo so far is Ken Rad Black Glass and Raytheons, which sound great.
Like you, I am very, very happy with the way the VAC amp sounds on my Daedalus speakers. What a spectacular match!
Enjoy!