Integrated Amplifier for Sonus Faber Guarneri Evolution

MA 9500 is a killer Amp.    Bluesound is good , but you have the foundation of a great system with those speakers so a good source will exploit what they are capable of. 

I went from a Vault 2i to an Aurender N200 and DAC and couldn't be happier.  Innuos makes good streamers too.  

Something like the MA9500 has a very good sounding  DAC card so you could do a network streamer without a DAC.  

I have had great success with Moon Simaudio amplifiers with SF speakers - I currently have a 700i driving SP Concertos and it is a completely effortless combination. I have heard the 700i driving more challenging loads like the SF Evos and it works like a dream. 

A wonderful integrated and better then pass labs or McIntosh ,hand built is Aacphase from Japan , either their E380 or even better sound their new E4000

At our audio get together I heard them all on the same weekend their attention to detail is superb unless you have $23k for theNew Gryphon Diablo 

which. Is the best but very costly . My friend bought the Accuphase E4000

the refinement and realism is fantastic , Perrotta consulting , is my go to for upper end like Accuphase .

My feeling is when it comes to these things, you'll never know a good match until you try it. Some great amps have been mentioned here but I'd add one to the list: https://www.audiogon.com/listings/lisb62ag-modwright-kwh-225i-stereo-tube-hybrid-integrated-amp-52620-tube.

For your money, this will likely be hard to beat and it's being sold from the music room so if you don't like it you can return it. This unit will have a beautiful balance of tube pre stage and solid state amplification. I have an LS100 pre and it bested everything else I've had in my system, including ARC, and not by a little. 

For what it's worth, I think this is a much better match than a Macintosh. My experience is that Macs match really well with B&W or another somewhat bright speaker; the pairing works out as the smooth Mac cools off the slightly glary highs. Sonus Faber don't have those elevated highs, their much more balanced and the Mac might make them sound mushy. 

Audition the Boulder 866 and you will be glad you did. Very neutral with plenty of power for your speakers. Good luck !