Looking for advice, recommendations

I am looking to upgrade my amp.  Current amp is Primaluna Dialogue Premium Integrated.  My speakers are Acoustic Zen Crescendo Mk II.  

I am currently considering two possible upgrade paths:

1.)  Primaluna EVO 400 Integrated  (about $5.5K)

2.) Go separates with a 6SN7 based preamp (such as Sachs) + SS power amp, possibilities would be a GaN Class D, or Benchmark AHB2.  (This would be about $6K with a Peachtree or LSA GaN 350 or Benchmark , to as high as $8.5K with Atma-Sphere Class D amps.)

I think my Dialogue Integrated may be marginal for my speakers.  I am looking for more power, lower output impedance (better drive).  Sonically, I like the sound of tubes.  I want a three dimensional sound, with well defined space around each instrument and vocalist.  Looking for more detail, without harshness.  

Any advice, recommendations would be appreciated.