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
My two cents...
I use a vintage restored McIntosh MC240 that sounded great with my Harbeth 40.1 (I no longer have). Looks awesome as well, it's definitely a showstopper when people come over.
My audio club friend drives his with an Audio Note Oto Signature SE. It sound fantastic as well and it's surprising what a low wattage amp can do.
With all that being said, I was on a trip to Southern California and visited a dealer down there who played me some Harbeths 40.1 driven by a Quicksilver integrated amp. I was floored, still am, by the sound that came out of those speakers. Now let it be said that his room was totally set for music like mine will never be but it was outstanding. 
Your best move is to a Bob Latino amp.  Either his 35 wpc ST-70 or the 
60 wpc ST-120.   The 125 watt M125 mono block amps would be serious
overkill for you unless you wanted to run them in 65 watt triode mode.  

The ST-120 is a Mac 275 killer.

You can get them fully assembled and tested as well as in kit form.  I personally love kits because I feel much more involved in the system, but most on this forum seem to buy their audio the same way they buy their luxury cars.

You see very few Bob Latino amps on the used market for a reason.   He's sold a ton of them, but people love 'em.  He also sells very affordable upgrade kits for the Dyna ST-70 and Mark III amps.