What tube amp for Harbeth 40.1


I am looking for a tube amp for Harbeth 40.1.  I know many suggest SS amp such as Accuphase, Luxman, Hegel, McIntosh ... etc for Harbeth, but I decided to keep it with tube.  I also don’t think I need a lot of power.  I currently have a 8W custom built 300B and had a 18W Almarro 318B, and to me, they sound fine.  However, I think more power will help, and I never know what I missed until I try it out.  Having said that, I don’t think I need crazy power.  Anything 30-80W is good enough for me.  I am 3m away from the speakers, listen to Jazz at avg 83dB.

i have the following short list:
1) PrimaLuna Evo 400 integrated
2) Leben CS600X 
3) Linear Tube Audio Z40

Which one do people like with Harbeth?  Any other suggestion?

Among all qualities, I value holographic presentation the most.  I really like the feeling as if the singer is floating in front of me, if you know what I mean.  And my current 300B do pretty well in this regards, and I read this is what SET amps are good at.  Will I be disappointed with the above?
Thanks.
gte357s

@pdreher ...but acknowledge synergy is key when it comes to matching tubes to tube amps and speakers.

What amp(s) are you using? Are they stock or upgraded amplifier(s)?

The reason I ask is a buyer of my last EL34 (Triode/Ultralinear) amplifier paired it with his Harbeth 40.1s. He called me shocked about how much better it sounds than his former mono amps originally 2x the price of the amp he bought from me. Over a year of messing around, we eventually concluded the upgraded coupling caps inside truly brought the amps/tubes to an entirely new level. Test repeated with four other amps, thus achieving the same results. He's carried that same amp to several buddies homes, surprised at the difference upgrades make.

Now truly hearing each tube difference now, due to the internal upgrades alone. I was stuck years back on tube rotation with little difference. Other upgrades, caps, opened a whole new door of sound. A local 50-year tech mentor helped us a lot. Always appreciate wisdom and experience from those who paved the way... :) 
Or LTA z40 Ref mono
92 wpc
Circa 1960 EL34 Mullards EF2

Phenomenal tone balance. DEAD quiet
@decooney

The reason I ask is a buyer of my last EL34 (Triode/Ultralinear) amplifier paired it with his Harbeth 40.1s. He called me shocked about how much better it sounds than his former mono amps originally 2x the price of the amp he bought from me.


forgive me if i missed it down the line of posts, but what amp are you talking about?
@decooney 
I use a vintage Music Reference RM9 MK2 refurbished by Roger Modjeski in 2017.  It's been the best all around amp in my 20 years as an active audiophile.  
@jjss49
It was a former upgraded Cary V12R (tubes, caps, resistors, internal re-wiring in a few spots) paired with a fully upgraded SLP-98 preamp. Then Mundorf EVO Supreme SilverGold caps (2nd cap upgrade) brought it to another level. That amp inspired the same upgrades on other amps with similar results.

@pdreher
Very Nice. A good friend who passed a few years back had your same RM9 MKII version, always enjoyed the opportunity to listen to it. That amp was the one that pulled me away from ss/mosfet amps to over to tube.