Integrated that blew you away

I've always been a separates guy but my second system has an integrated amp.  It sounds great, I'm pretty confident I could have spent more on budget separates and still not have gotten the same performance.   That amp is a Cyrus i7XR.   Way too small for your needs but it's a great example of how good an integrated amp can sound.  

My Dad has the McIntosh MA8950.   That is a seriously good amp.  The built in DAC sounds excellent.  He has it driving a pair of Sonus Faber Electa Amator III anda REL S/510.      It's a great amp. .

Moon/ SimAudio makes great integrated amps too.   

Definitely want to home demo amps in that price range if possible.   

My favorite integrated is the Synthesis Audio A 40 (40 wpc KT -66 tube) or their A 100 amp (100 wpc KT-66).  Both have built in DACs that are good and remove control.  The only major negative, to me, is a lack of balance control.  I hang out at an audio shop and I get to see how shocked some people are with the sound of these amps.  Most who take these home for a trial end up buying.

I have separates, but would have no problem with either of these superb integrated amps. The Nagra is lighter and more compact so it might be better for downsizing

Nagra Classic Integrated amp

Jadis DA 88 S

burmester 032 and 232, both are superb

I am going to agree with @larryi. I have had the A40 in my system and wish I didn’t sell it, I would now like to use it in a secondary system. Has a great built in DAC as well. If you want a bit more power the A100 is a nice upgrade. The only reason it is no longer mine is I upgraded to separates. 
 

john