You have a nice pair of speakers kielecki and at 6 ohms, 89db sensitivity, a very wide range of integrated amps will properly drive them.
So what is really needed here is budget in order to get a meaningful and realistic suggestion. Or else you'll get recommendations for 20-45K amps like the ones above to drive your $2500 speakers.
kielecki, I have Audio Analogue integrated amps to drive SF Venere 2.5s. I previously used AA Verdi 70 and now I use AA Maestro 70. Very happy with the sound. As paraneer said, with 6 Ohm impedance and 89dB sensitivity you have a wide set of options. It all depends on the sound signature you like. I had SFs driven with DK Design VS-1 MKII (150 @ 8Ohm) but the AA (70 @ 8Ohm) I feel is definitely a better combo.
The AA units have a very sweet and mellow sound.
Good Luck with your search!!
Now that I have that out of my system, paraneer is right, you have a nice set of speakers with lots of flexibility. In addition to your budget, it would be helpful if let us know what other components you intend to use (cd player, turntable, music server, etc), the size of your room and any shortcomings of your current system which makes you want a new integrated. Once we have that information, we can provide you with much more focused suggestions.
In that price range, I would take a look at the Parasound HINT ($2,500) as it has nice power (John Curl design, too!) to drive your speakers and already has an excellent built-in DAC.
I have a Bel Canto C5i and really enjoy it. I don't have Sonus Faber speakers, but my Golden Ear Triton 7s are similar in terms of sensitivity. The C5i is much more powerful sounding than its 60 watts a channel (8 ohms) would indicate. Power fully doubles at 4 ohms which indicates a good power supply. The sound is very smooth in the highs -- quite tubelike and extended -- and the bass is deep and solid. I have been very pleased with it. My only criticism is the display -- one would think in this modern age of electronics that they could do a little better than the green calculator digit display. However, it is a great amp for the money.
Kielecki, I have owned the Peachtree Nova, Bel Canto, Hegel 300 and Hegel 160. The speakers I have are Joseph Audio RM25XL Mark 2, these speakers would be considered in the same range as yours.
The Peachtree was a nice warm sound with good imaging and depth but not near the Hegel level, which isn't surprising based on cost. I couldn't connect with the Class D Bel Canto, tried for months, finally went the Hegel route. The better your speakers the better the Hegel's sound. I demoed the Hegel 300 with a pair of Focal Sopra No.2, and it did everything I was used to but on a whole other level. Not just a step up but a major leap, what I am trying to say is the Hegel has many higher gears in it and would support speakers at 4 times it cost should you ever decide to go to a higher level speaker in the future, which I am now doing with the Focal's. Test the Hegel's they are really good, also plenty of reviews available. Just my opinion. Happy hunting.
If you prefer SS gear, buy as good a Hegel integrated as you can afford. I heard a three of them demonstrated, from the least to the more expensive at an audio show, and while the least expensive amp sounded gear, the two successive sounded increasingly better, with the H300 absolutely superb. There are as neutral an amp as I have ever heard.
You will no doubt get a lot of suggestions so I will add what I can
I have owned and used Sonus Faber speakers for about twenty years now currently I run Guarneri Homage the originals. My amp recommendations would be
David Berning ZH-270 ( My previous amplifier) A true classic and this amplifier was used by SF to voice the Stradavari I believe.
LSA Statement ( This is the amp I currently use )
Line Magnetic 519A could be worth a listen as could the Mactone which is used by a very knowledgeable and experienced audio friend who also runs Sonus Faber speakers.
Yes the Gryphon and Dartzeel amps are wonderful but I am not sure you need to spend that much money as if you do your speakers will likely become the weakest link.
I have owned quite a few integrated amps during the past 20 years along with separates, ranging from the mcinstosh 6500, Lsa, rogue audio Cronus magnum, and the Hegel h100 and now the Hegel h300. The Hegel 300 is awesome and includes a decent dac if you don't have 1, I use an external dac. I had the factory change the ht bypass port to another RCA audio input. If you like tubes, the rogue Cronus magnum with the kt-120 tubes.