Thanks for your answers.
Yes, while visiting Paris with family, I took time to do a quick listening at Cobra store. Only this amp, and was free to change speakers, so, tried the ones in the auditorium quickly, but, it was enough for me to conclude that 40s were my favorites ones with this Playstream A7. There was a PM8006 but in a different auditorium, so, not able to try with it.
I have not listen to much amp earlier, so, don't know the Musical Fidelity, Belles, Vincent, etc. I know the names, but that's it. And they are not available in lots of stores.
I listened to a Cambridge Audio CX-A61 and a Marantz PM7000N in a different store, with Dali Oberon 5/7, and I preferred the sound of the Marantz, and really liked it with the Dali. Maybe some Opticon 5/6 would work fine with it too. I tried the PM7000N with Kef LS50, but it was really lacking bass, I did not liked the sound at all.
I ordered a PM8006 and ND8006 to replace my old Denon AVR4311, back to stereo.
Marantz seems to be well build and easy to use (not only by me).
Will use the DAC with my PC, can play all my CD/Flac from NAS, can still play some CD, and probably will take spotify premium or equivalent (even if not highest sound quality, don't plan to pay 20€/month for higher quality for now, but need to test/compare with free trial).
A detail, but I have rejected amps which can't really be put in stand by mode, I don't want something always on, eating 25w or more 24/24.
So, this is not perfect product, but choice made of compromises, and which sound good too.
We can find some used s40 around 2000€, this is quite expensive still, but, if that works well... I was impress by the sound of these bookshelves compare to other speakers, and was thinking that small speaker was maybe better in my "not so big" room.
Finally, problem with all that, is that we can't really test in our room, which can completely change our feeling.