You have done already research on your own...
KEF R3 speakers are excellent and to beat them you have to increase your budget. I recommend also looking at Dynaudio Evoke 20 and Sonus Faber Sonetto II.
You have chosen well already with MOON by simaudio Ace or Naim. You can look also into Linn or Copland amps. Though the Moon or Naim are offering a lot with all in one concept but if you are asking me I will go with all separates. If something goes wrong or you don't like something you can replace one component and this will improve/degrade sonic abilities of your system.
I will also look to build with smaller format components if the space is an issue. Also you may look to reconfigure your space to be more suitable for music and work.
Small format components are available by Schiit Audio. IE. you can start with Saga Pre-Amp and Vidar Power Amplifier, maybe add second Vidar later and bridge them. As for the DAC you can look at Chord Qutest or similar (my knowledge of the DAC's are limited). You just need one streamer and that will be all. For streamer look at Bluesound or Yamaha and for dirt cheap at the beginning you may use also Chromecast Audio, though discontinued, but still to be found and use their optical output to DAC. You may look down the road to upgrade your pre-amp if you do not like the sound as that will be weakest component mentioned.
Personally I think that Saga/Vidar combo sound-wise will beat the all-in-one solutions you have looked at.
Just for your info: I have listen to Devialet Expert amp and did not find justified the price nor the sonic qualities. It was connected to Devialet Phantom's as well as Monitor Audio and Focal speakers. For the look the Devialet combo was amazing but for the sound Focal's were much better.
While I am in Canada I also prefer local companies (MOON by Simaudio, PSB, Bryston, etc.) for the sake of warranty or even ability to drop off the component if something is wrong. Also to support local manufactures. Needles to say that PSB acquired NAD few years back, speak NAD is also under Canadian flag.
Hope this helps...
EDIT: Naim or MOON by Simaudio as well as Copland amp combined with Klipsch Heresy III speakers as someone mentioned above is also something to look at, though not for everyone's taste... for this I strongly suggest prior going somewhere and audition them.