High end high quality int. amp for low level listening

Hello to all Audigon members.  I'm quite in a dilemma weather I should upgrade my amplifier. Currently I own Pathos classic one MK3 driving Sonus Faber Sonetto's speakers, and I must say I'm very happy with sound filling my 35 square meters room. However, it's known that the speakers are power hungry as they rated at 86db sensitivity and 4 ohm impedance and I think they will surely benefit from a bigger power supply. With all that being said I'm not sure if I will hear any improvement mostly because 90% of the time I listen at ~60dBs SPL. My budget is around 5k $ and these are the amplifiers I've been considering:  Hegel H390, Anthem STR, Cambridge Audio Edge A, McIntosh MA5300/MA252, Accuphase e280, Rotel Michi x3 or used Pass Labs INT 25, Mark Levinson 5805.

What do you think guys, will any of the amplifiers make ay difference at 60dB SPL ? 
Add 1-2 REL subs. What you are missing is that bottom end. I can listen even below that level because of subwoofers. So take $1500 and get a T9X or double for two. If you decide to change your system for an integrated amp the Hegel line is really good. They do sound great at low volume. I just had a H190 at my place for a demo and I was amazed what $4000 could buy. See if you can demo some subs and a Hegel to see what works best for you. Low listening is about the preamplifier. There are ways to cheat the system. My current system without subs can be at 2.5% of the total volume. It is how it is made. I will say if you are using Revel or JBL HDI speakers then Mark Levenson is a good choice. Upgrade the power cable to the Mark Levenson so you can remove some of the hash and give it a better gauge to let it breath. Have you ever tried to breath through a straw while doing jumping jacks. That is what your amp and preamp are doing with a 16 gauge power cord. If you happen to live near or within driving distance to the Chicagoland area this store will let you try almost anything in their store for free in your home. No buyers remorse. Plus, you get to hear a product that is full broken in. https://holmaudio.com/
I hope this helps you out. 
@hshifi Thank you for your feedback. I actually have 1 SVS sb1000 sub with crossover set at 50hz. I agree it really makes a difference, especially at my listening habbits. 
More powerful amp = better at HIGH listening levelYou want amp with better LOW RESOLUTION DETAIL.The higher the power, the WORSE the low resolution detail gets.These are dictated by the laws of physics.Due to attention to execution you will see some variance though. Some high power amps can still do pretty decent low level detail, but same quality of execution will give way better low level detail with lower power.
@realworldaudio tbh i wasn't aware that higher power amps have lower resolution on low level listening. Can you name any specific integrates that have great resolution on low level listenings? 
These are dictated by the laws of physics.
(Does the quanta of an electron get bigger in bigger amplifier?)

@realworldaudio tbh i wasn't aware that higher power amps have lower resolution on low level listening. Can you name any specific integrates that have great resolution on low level listenings?
I would suggest some questioning of the factualness, and proof of various claims, would not be a wasted question for you to ask.

I do not want to come across as too harsh, but it is a low probability that all these solutions can exist simultaneously as optimum solutions.
(You have been told so far):
  1. To use more sensitive speakers
  2. More powerful amplifier
  3. Use a less powerful amplifier
  4. Use Subs
  5. Use tone controls and loudness controls.
If it loud enough now, then we can exclude #1, #3 immediately. #2 we could exclude with a volt meter or an oscilloscope… Or I previously excluded it using just a pencil. 

At least three people mentioned tone and loudness controls for low level listening. Does your current amp/preamp have that?
There is a lot of info on the net about tone controls and Fletcher Munson curves.

That puts the #4 (sub) as potentially having some merit if it was I used as a way to have tone control.

If you are happy with it (which you said you were in the opening), then doing nothing is a pretty safe bet, and it is in between having an amp with more power and less power.

That leave #5 (tone controls), via a preamp, as being the only thing to look at that has any rational basis in fact.

The other reason to change things would be purely emotional. That is not bad, it is just not reasoned.