Wilson Sabrina X ... oh my God! and Jadis... or?

Looking at the comments above, VAC does not sound solid state.  It is a modern tube sound so it won't sound flabby, but is not sterile.  Bigger concern is the miserable impedance values based on the measurements I have seen for Sabrina X. Min impedance is 2.43 ohms in a beefy part of the frequency range. This is not a good profile for most tube amps.  

I would look at amps that can deliver current which will give you the cleanest, clearest bass response.  This tends to be SS but some tube designs will work.  

I have no idea what your budget is but the AVM Ovation 8.3 is amazing with a tube input stage and oodles of power.  I have people driving a lot of great speakers and it is a GOOD match for the Sabrina X.   

Naim is a nice match.  Top line power isn't huge but Naim products basically thrive at 2 ohms and will handle the impedance issues well.  You would need separates but at least they have stopped with the stupid DIN connectors and moved to XLRs.

AGD would be brilliant as it is capped more by your home breaker in terms of current draw than by the amps power supply.  Efficient and sweet sounding, this is my go to when folks are moving away from tubes but want to maintain a liquid sound.  Separates again though but all extremely small components.    

The other really interesting integrated would be the Riviera Levante.  30w in Class A, 150w Class AB and a tube input stage.  I had someone move from a VAC Master Preamp and Allnic Monos and they did not feel this was a step back as they downsized.  

Octave with the Super Black Box will do the job well.  Tube choice really matters though and I would need to check with my rep to be reminded of what he suggested.  

@verdataudio thanks so much for your help. 

Will start with my Duetrenta in Pentode mode, then will try to test the AGD which really appeals to me. Tempo di Gan, good choice?

The Tempo is their entry level and best value IMO.  It delivers a solid 100w into 8ohms and doubles down till you trip the breaker on your outlet or I think you hit 20 amps.  Point is, impedance is a non-issue.  Tempo will also probably be more resolving and detailed than a pentode based tube amp.  

That said, the Duets with 150w of power into 8ohms would probably be my first choice but quite understand if you don't have 2x the money lying around.  It is easy for us dealers to talk about better options but budget practicalities certainly matter

The above is why---contrary to the common wisdom that an OTL amp is the best for use with the original QUAD ESL, the exact opposite is true. The QUAD has one of the most wildly-varying modulus-of-impedance curves in the history of hi-fi (from below 2 ohms to over 100, depending on frequency!). Used with a high output impedance amp like all OTL’s, the frequency response of the QUAD is drastically effected. Not good, obviously. I originally used a Bedini 25/25 (solid state) with my QUADS, a classic combination.

@bdp24 Quad ESL57s and 63s word great with OTLs! Neither drops below 4 Ohms in the highs so no worries. We have lots of Quad ESL customers.

@superelmar As you seem to have noted, there are class D amps now that have the same smooth mids and highs of the best tube amps and no problems driving lower impedances.

FWIW other than impedance the Sabrinas have always been a fairly easy speaker to drive. Most tube amps on the 4 Ohm taps should drive them just fine. But since class D amps have made such advances I don't see why to do tubes at this point.

I’d love to get top notch AGD or Java, or Aavik, etc but most of the cash went for SabrinaX, and now need at least to wait at least one year for a nice amplifier, these ones been offered, second hand or ex-demo, ideally with a good phono or dac inside, or both!

Audio Research GSi75 6.500€
Audio Research I/50 3.000€ with phono stage
Pass Labs INT-25 6.500€
Jadis DA-50S 4.000€
Aesthetix Mimas 4.600€
VTL INT-85 3.500€
Mastersound Duetrenta 2.500€

Regarding the i/50, I got it paired with Zu’s Omen I wasn’t impressed, better than the Pass Labs INT-25 (what a disappointment), but a toy compared with the Mastersound Dueventi which is Pure Class A either SET (10wpc) or SEP (20wpc), what bothered me that having 50wpc and with all the bells and whistles , it sounded less powerful than the Mastersound. On the other hand, at dealers with demanding TAD ME1 sounded so nice…that’s why not sure about GSi75, at the end dealers told me that if ARC, much better separates, even the Jadis according to him, sounded nicer and powerful than either i/50 and GSi75, but damn it, would love an American amp, after tried many stuff, I really miss always American Bold big sound, but those Wilson Oh my God, not a single frequency was out, all super balanced and coherent filling the room.