Help an old man out

That's the same BS you hear all the time. It is shocking the number of people unable to figure simple things out and seem to think truth is a democracy.

88 is low, impedance is a crock. Look at all the guys with trouble driving speakers. Why they blame impedance is beyond me. These are the same guys who told me I should get "easy to drive" 8 ohm speakers not 4 ohm, because I have a tube amp. Every single one said 4 ohms will be worse. Everyone except the guy who actually makes the speakers. So I went with his advice. At 4 ohms they are super easy to drive, sound awesome and guess why? 98dB! 

The difference between the 88 you think is "middle of the road" and 98dB is TEN TIMES the power. What I get from my 50 watts you will need 500.

That is reality. 500 vs 50. That is physics. You can make up all the stories in the world, nothing will change the fact that 10dB is ten times the power.

Middle of the road by the way is where you get run down by traffic going both directions. Middle of the road is the last place in the world you want to be. Unless that is you want to be run down no matter which way you turn. https://youtu.be/mikj8eDKxMQ?t=11

OP — I have a few thoughts to take or leave:

I own an NAD M33.  I think it sounds pretty good.  I’ve been comparing it to my Prima Luna HP Dialogue Premium integrated, using KT150 tubes, in an office sized room.  I’d give the edge to the PL, but that’s my ears, my room, my NOLA Contender 2s, etc etc.  I will say, I continue to dislike the BlueSound environment.  On a less subjective subject, the NAD is not Roon certified, if that matters to you.  Unlike earlier released models that are grandfathered in, if the NAD M33 was sold after Sept 2020, Roon will not recognize it pending certification.  Many online dealers, perhaps in-person dealers, are pitching it as Roon ready.  It’s not.  Lastly, reading between the lines of the reviews and the buzz, the focus with the NAD seems to be its all-in-one feature profile.  Yes, it’s an accomplishment.  I just don’t see a lot of buzz about the sound.  Some.  Not a lot.  

More generally, I think $5k can get you a helluva good amp.  And if you are not philosophically offended by Class D, you might consider some of the amazingly well-priced PS Audio amps.  They’ve been well-received.  I owned the BHKs a few years ago, but I have not heard their Class D stuff.  But, on paper, worth a look.    
Impedance is emphatically not a crock.  Dan D’Agostino would not say that.  Nelson Pass would not say that.  Bascom King would not say that.  Call Nelson and just ask him.  Nominal impedance specs (e.g., "this is a 4 ohm speaker," or "this one’s an 8 ohm speaker") may be unhelpful, or perhaps even "a crock."  Nomical impedance is sorta just average impedance.  But impedance dips are incredibly important, and have little to do with wattage, and little to do with sensitivity.  If a speaker has an impedance dip down to, say, 2.0 or 2.2 ohms at, say, 85 Hz, that speaker is going to be asking for a decent amount of current (not wattage) at 85 Hz.  And a little amp won’t have what the speaker is asking for.  In a way that impacts sound quality, not just volume (which is arguably all that sensitivity numbers tell you; a test tone of 1000 Hz, delivered with one watt, measured from one meter, gives you X volume, in your case 88 dB — although, I suppose if you love listening to 1 kHz tones all day, that could be enormously important).
Turning to the practical: a speaker with sensitivity of 88 dB pretty much never needs 500 watts.  Betcha the NAD, at 200, provides plenty of headroom.  It was plenty of power and current with my Harbeth 30.2s, with their low sensitivity.  And if you don’t feel like really geeking out on impedance dips, etc, I’d vote for you to keep your sights on the 100 wpc and higher amps and chances are you won’t have any power/headroom issues and can instead focus on other priorities (tone, clarity, imaging, dynamics, grip, air, lack of glare).  
My two cents.  Worth about ... two cents.  

i agree with the earlier suggestion of a hegel - h190 or 390 would work well for your power needs

simple elegant styling, excellent sound, plenty of power, very nice remote

JRW,  thanks for the post...agree with you 100%.  The S300 could drive the Gallos okay, but I wanted that headroom and control and the only way to go is up.  
How is soundstage comparatively between your M33 and your Prima Luna?  The reviews I have seen that focus more on the sound of the 33 have said the new Purifis make a huge difference in sound...big improvements over the n-cores etc. when it comes to tighter bass and even lighter highs, which my s300 def lacks.

WAF...that is awesome lol.  Mine is actually very understanding.  She is the one who told me to get the M33, but she is pretty supportive of my hobbies, even when they get expensive.  I showed her the Sonus Faber Serafinos that are on auction right now and she loves them...still waiting for her to tell me to get those!

Headphone dreams/JJS, following your posts I went back and relooked the 390...it is definitely a consideration. Looks quality!