Looking for a simple system

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 ...