Looking for a simple system

If you like Gato, and do not need streamer and integrated combined, I would look at the top of the line Gato Amp 150 (ClassAB),  and a separate streamer...

We are an atoll dealer their  gear is great and can be auditioned unlike Gato they have a US. importer. 

We have hear previous Buchardts at Axponna and felt they were okay very over rated also impossible to demo, however  the new e50s do look good on paper the gershmans are excellent loudspeakers:

we would recommend looking at the Alta audio alyseass

unbelievable deep bass down to 32hz, via a unique patented composite, transmission line/infinite baffle bass loading design.

great clarity from a superb ribbon tweeter, and a proprietary custom titanium former long throw midrange woofer.

very inert composite cabinet

https://altaspeakers.com/product/alyssa-speakers

just an extraordinary performer for 5k.

Dave and Troy

Audio intellect NJ

Atoll and Alta dealers

Go with the Electrocompaniet ECI 6DX MKII. I own pass 250, Mac 352, Accuphase 380, Hegal 390 and the above. You cannot go wrong with the electro. Check the reviews out. I am astounded how good this amp is. I also own 12 pairs of bookshelf speakers. The Buchardts are outstanding. I have the special editions model and I love them. I also, have the E 50’s on the way. Mine will b here Monday. In my collection is the PS Audio Fr 5. This is also an outstanding speaker. It has some of the best treble I’ve heard. 

Let me know how the e50’s sound.

My two cents: I've owned an Atoll integrated (IN200SE) and it paired really nicely with the Fritz Carbon 7 Mk. 2 SE. It had good power and just a bit of extra energy in the mids and highs, so the Fritz's speakers warmth and soft dome tweeter were a great match with that amp. 

It's no secret how much of a good value I think Fritz's speakers are — especially given that there is no overhead, marketing, advertising, etc. I really believe they are easily the equal of speakers more than 2x their price. Review is here.

I’d go for the Atoll and get these Joseph Audio Pulsars.  Best of luck. 
 

https://www.ebay.com/itm/186915696094

IMO, as mentioned in other posts and reading many reviews, and I’ve auditioned them for hours, get the Kef LS60’s and be done, maybe get 1 or 2 of their subs. This will outperform most of the gear mentioned above and be the simplest to own and use. If you compare the technical aspects of the features the equipment mentioned above, the Kef’s has more features and the sound quality is fantastic. 

I would also seriously consider the Kef LS60. Huge sound value with all the features you seek.

Might also consider a preowned pair of Dynaudio heritage specials or Contour 20. 

Since you are just looking for something that will allow you to stream check out  Naim products. You can find fantastic previously owned Naim Uniti Nova and there are apps that you can directly stream from.  The Nova is a Solid 80 watts per channel and has numerous connections on the back including Ethernet.  Get a REL T9x sub and you will still have about $5k left for terrific speakers. I have also owned Atoll and it’s nice as well but love the Naim sound. Good luck and let us know what you decide to do. 

For something you haven't considered, check out the Anthem STR Integrated. I have owned one, and it is really good. Superb build quality, 200 watts into 8 ohms doubling into 4- significantly more power than the Atoll. I believe the Buchardts are 4 ohn speakers, not the easiest to drive, but the Anthem would handle them with no problem.  Includes a great DAC, but no streamer for $5,000. You could easily pick up a good streamer-Wiim, Cambridge, Holo red, etc., for under $1,000 and the Buchardts and be set with a great system that offers lots of future flexibility. The Anthem includes ARC room correction technology which is really good and helps you get the best from tour system. Worth checking out.

Lots of good choices-good luck.

If I were you I would look for an integrated streamer (Streamer / DAC)  integrated amp (preamp and amp). Having all four functions in one box I think it too much compromise and makes later upgrades difficult. 

or https://speakerchoices.com/

I've always been intrigued by an affordable (when used) bookshelf speaker that gets close to full range like the GS II, but after taking a look at user feedback from a few years back... 

https://forum.audiogon.com/discussions/gershman-studio-2

I also suggest that you wait for reviews from trustworthy reviewers before pulling the trigger on either the E50 or the GS II.

Go KEF active speakers!  So many advantages ...

I already have some active speakers so I am not interested in Powered Kefs.  The are the cabasse pearl akoyas