Aleph 4, or else? (good general purpose class A amp)

I have a question on Aleph 4, other desgns by Mr Pass, and older class A solid state amps in general:
I am looking for a solid state power amp to complement or replace my 300B SET (kit from hificollective.co.uk, built by them). 300B is fine with my 15 Ohm Lowther DX2 Fidelios, but I intend to buy (or build) some other speakers. I sort of like "the English sound", but other than that I am quite open and curious (wondering about open baffle, planars, etc., yet reluctant about very low impedance or extremely inefficient designs).
I am in continental Europe (Belgium), and I do not really consider shipping from the US.
In Europe the most acessible and readily available Aleph amp is Aleph 3. Aleph 2s are desireable, but rare; Aleph 5 seems to be pointless.
But what about Aleph 4? They are relatively rear, but there happens to be recapped one on offer, and I better decide soon...
As a general question, are they, in particular Aleph 4 (but also Aleph 3), restrictive or not when it comes to the speakers?
Aleph 3 can provide impressive current down to 2 Ohm, but otherwise it is a 30W amp.
Aleph 4 is a 100W amp, yet its current output seems to be on a par with Aleph 3 (- am I right???).
To complicate things, there are old Krells (thinking only about the first KSA50, fixed bias + fan) as well as Mark Levinson (I may consider ML2 and ML20.6, expensive as they are). I considered early McIntosh (MC 2505, 2105, 2120, 2125, 2200, 2205), but I dropped that idea.
In a nutshell:
- Does Aleph 4 take care of, like, 90% of 'reasonable' loudspeakers, or it is not the safest bet?
And, if Aleph 4 imposes considerable restrictions, would you say that its other qualities outweight its limitations, or there is a more universal option?
Again, all this is to be seen in Europe's second hand market setting.
P.S.
FirstWatt is a horse of different colour, but a thought about a F6 crossed my mind.