Well, the nice thing is you’ve picked an all-round fantastic amp! There’s not many at all that are higher than it and most still around the Luna’s price point are just ”different flavors” essentially. I’m nearing the top of my summit myself and it’s been a fun journey. I get it though, some don’t want to (or need to) go through the full journey. Tube-rolling is still something to do.
I am still a big solid state amp fan, so the need for one to fill my fancy is there (hence the reason why I ended up preordering the Zahl HM1). I would highly recommend checking out any and, if possible, ALL the ones you mentioned to see what suits your needs, too.
I’m really happy with my headphone cables — would recommend checking out Arctic Cables and seeing their offerings as you are begin looking. Love, love, love their Opera v2 for the Susvara (and I also have their Talos v2). Others have their own personal brand recommendations, but my experience with AC has been stellar so far.
I’m with
@orrman though, I think you are bottlenecking the system a bit with the Qutest. I really, really like the Ferrum Wandla, but I think I might land on the May KTE eventually. Just really like the Wandla though, so it’s hard for me to want to jump ship. Not only Chord or Holo May, but you could also take a close look at the Denafrips Terminator 2 or the Rockna Wavedream if you‘re reaching for endgame DACs, too.