Solid State Power Amps

I will echo the suggestion for Bryston amps.  They come with a 20 year transferable warranty.  They are built to last.  Of course they perform well.  But at this price point,  you want something you can depend upon.

A close friend used to be the McIntosh repair tech at the House of Music in San Francisco.  He saw plenty of broken Mac gear and knew it wasn't worth the money people were spending.  They made their rep with the old classic tube gear and have been living off of that for the last 50 years.  They don't have a 20 year warranty...  Go with Bryston.

take a listen to Ayre stuff

+1 for Paass (especially 260.8) having owned them and are still mated with a ARC 5se. It has allowed me to get off the upgrade  cycle as they are about as good a pair as I would possibly want. Left Levinson and never looked back....

I do not think you will have any regrets with them

The availability of Chinese copies of some of the great European amplifier designs like Dartzeel NHB108 and FM Acoustics 300A has made spending that sort of money on an amplifier redundant.Class D was supposed to do the same but from what I have heard it falls well short.You are better off buying a Chinese clone/copy and spending the other $23,000 on room treatment and speakers.Plus I suspect the copies will sound better than most of those $25,000 amplifiers.$40,000 might get you something better- [the real thing].

If you must do it at least buy something with premium build quality and service support like Accuphase.

There is a massive amount that can be achieved with $25k, limiting it as a spend on an Amp' only, is parting with a substantial amount of 'Mark Up' for somebody.

One will get many short lived friendships fast making such intentions known publicly. 

$5K will discover an exceptional Amp' , the task will require footwork.

Footwork can introduce one to individuals who become friends that develop into ling time sharing of an interest,

I suggest trying to learn if a Neurochome Power Amp' can be used for a demonstration, the most bespoke built, will still leave $22K in the coffers.

FTR, I have heard Neurochrome in A/B Comparison to $50K Soulution Amplification, using a System inclusive of the Soulution Amplification that has a value of approx' £200K. No real winner between the Two Amp's was to be  easily identified, if it were a contest.  

Soulution as an Amplification can easily be added to your shortlist if in there were models produced to suit your price range.