Suggestions for Harbeth P3ESR speakers

Last year I purchased a used pair of P3ESR speakers in cherry finish for my study. The gentleman from whom I bought the speakers also had a Naim Unitiqute (first version) that he sold to me at a decent price. While I liked the combination, I always felt that the Unitiqute was a little under powered for driving the Harbeths to their full potential. To make matters worse, the digital display (green LCD) on the Unitiqute started to fade and eventually went out after a few months. Searching on the internet revealed that this is a common problem with Naim amps. On one hand, they recommend that the amp be kept on at all times for optimal performance, but on the other hand they use substandard parts for the display. What a shame! So now, while I can still listen to music, I can't really see any information on the amp. Cannot listen to the internet radio, which was a feature I enjoyed, anymore 'cause I can't see the display.

So now, I'm in two minds. Will getting another amp make the Harbeths open up further? Or am I better off selling them and trying something else instead. I already have a pair of KEF LS50 Wireless that I really like and enjoy. KEF has come up with a smaller version (LSX), which is worth a try.

If I decide to stay with the Harbeths, what other amps can you folks recommend? 

Limitations: Have to buy used, under $2000 preferably. Small footprint preferred since it's in my study (10x12x12).

Music: Mostly jazz (including modern), vocals (Diana Krall, Gregory Porter, Nina Simone), soft/psychedelic rock -- Pink Floyd, etc. Sometimes I do listen to hard rock or mainstream pop also. Don't really listen at high volumes mostly but do like to crank it up every now and then.

Lastly, I think adding a small, fast, and musical sub might also help. Recommendations in this category are also welcome
Sorry, forgot to add that it has to be an integrated due to space limitations. From what I've read, the Harbeths favor SS over tubes.
Get a used Peachtree integrated amp!
There is a Peachtree Nova 150 for $1400 with free shipping from "peachtreeaudio" on EBay. Refurbished and with a two-year warranty! Including a high- quality DAC and phono stage! Get rid of that Naim!
The P3s sound great with tubes. 50 watts in that small room is sufficient to drive them. There are a few Rogue Audio integrated amps listed here within your budget that would fit the bill. I use a JL Audio Dominion with my P3s and it is a perfect match!
I agree with @yogiboy that a sub will open up the P3s. Adding a (used) B&W ASW610 to my P3s made a big difference. I chose a sealed-box sub to mate with the sealed-box P3s.

I’m using a powerful amplifier (Marsh A400s), and I like the combination a lot. But it’s not an integrated; I never compared another amp; so I can’t say a lot here. Still, I would avoid any SS amp much under 100 watts or tube amp much under 50. Sealed-box speakers, in my experience, benefit from power.

The LS50 and P3 have fundamentally different sounds. I prefer the latter and find it less fatiguing, despite the many good reviews of the LS50. (On the other hand, I believe the W versions use DSP to improve the frequency response.) I suggest an extended and careful audition before buying.
@roberjerman: Thanks for the advice. I actually owned a Peachtree Nova 125 for almost two years. It never really impressed me. It was a bit too sparkly on the top for my taste. Also had some quality issues. Finally replaced it with a Parasound. The difference was night and day. Now admittedly, this was almost 5 years ago. It is possible that Peachtree has made improvements since then.

@yogiboy This is interesting. For some reason I always thought that Harbeths go well with SS. I think even Alan Shaw recommends SS over tubes. But TBH, I've always been intrigued by tubes. Maybe it's worth a try. Thanks for recommending Rogue Audio. I'll check it out. They have several models on sale @ audiogon. Which one would you recommend?
BTW, someone local is selling a Primaluna Prologue Premium integrated for $1500. Has anyone tried it with Harbeth? 
You should make an offer on that Atlas Magnum that is listed for $1895. It is a demo with full warranty. It looks like the seller is a Rogue dealer! My friend uses Rogue tube gear with his P3s and I use Quicksilver tube gear with my P3s and both give outstanding results!!
Although everyone hears differently, the Naim is generally considered to be good match for the Harbeth, only when you go up to the separates. In my experience, the Nait XS and lower range integrateds do not cut it when matched with the Harbeth. In my book, the minimum level for my standard is the NAC 202 / NAP 200 separates. I’ve briefly tried the Nait XS with the Harbeth Super HL5 Plus and it sounded good but mediocre. The Harbeth sounded more poised, open and special with the 202/200 and even more spectacular with the 282/250DR.

The Unitiqute is inferior to the Nait XS so I expect the P3ESR to sound mediocre when driven by that all-in-one. If you would like to hear the P3ESR near to its full potential, do explore other amps such as LFD Zero LEIV or V and Sonneteer Orton to name a few. Or perhaps Exposure 3010S2 at a lower level. Otherwise you may try some tube designs as I am quite sure the P3s will sound much more open and exquisite when driven by some of these select amps. Some Harbeth owners have reported great success matching Leben and Jadis Orchestra Reference to models ranging from P3ESR, C7ES3 to the M40.1.

Based on my experience with the Nait XS driving the Harbeth, I am not surprised that you find the P3ESR and Unitiqute combination to sound lacklustre.
@yogiboy  The Atlas Magnum ... the retail price is $2395. The listing is for $1895, i.e. the price is less than <25% of the original price. When buying used, I try to find deals around 40% off of the retail price. Yeah, I'm cheap like that , lol! Otherwise, it sounds like a really nice piece of equipment. Thanks for the suggestion.

@ryder  Your analysis is spot on. I really like the Naim sound, but you're absolutely right that their lower end equipment is under powered. The Unitiqute, when brand new, was listed for $2400. Given the quality issues with the display (more widespread than you would think), and the lack of sufficient power, especially in comparison to competitors, I'm just surprised that people still buy their lower to mid end gear at those prices. TBH, I'm kinda bummed out after the quality issues. Appreciate your suggestions.

I'm seriously considering purchasing a used tube integrated. Given that I have zero experience with tube gear, I'll do my due diligence and do some research before jumping in the pool.

So make an offer at 40% off the list. I doubt that it will be turned down. What do you have to lose? BTW, there is a Cronus Magnum listed for $1200!
Honestly, I’d look into a sub first; then change the amp. Even a Boulder amp is not going to give the P3 any low end. Not to detract from the need for more power, but that would be my priority.

What’s important in the sub is to choose a sealed one, to blend with the P3; one designed for music; and one with as much signal processing as you can afford (low-pass filter, adjustable phase, EQ). That stuff help attain a seamless blend.
Arafiq, I would agree. Similarly I have read about display issues of the newer Naim gear. At the prices that Naim is charging this should not be happening. My Krell KPS-30i is close to 30 years old and the display is still working flawlessly until today. It is fortunate that all my Naim gear do not have displays (NAC 202 and NAC 282).

The lack of power is a valid reason to the underperforming P3ESR. The speakers do respond well to more powerful amps.

A sub will help with the bass by augmenting the frequencies which the speakers fail to reproduce. However, the right amp will not only improve the bass of the main speakers but open up the midrange and treble. The presentation of the Harbeth can be very different with a suitable amp particularly tubes. Some solid-state amps will also produce the results but be cautioned, the P3ESR may not sound much different if you pick the "wrong" amp.
I have P3ESRs with a Rogue Cronus Magnum II all tube integrated and the combination is fantastic. The CM2 is a 100w integrated. They have just come out with a CM3 that's $3,000 so many CM2 have hit the market in the $1,500 price range. And the "2" is very good as it is. The "3" added a few new features, but really the CM2 doesn't need upgrading.
Thanks for the suggestions everyone. At this point, I am quite certain that I will drive down the tube route this time around, followed by a fast, small and musical sub. Keeping an eye on the deals here and local craigslist.

The Rogue Cronus, and Rogue Audio in general, seems like a good choice. Naim is out for good, what a disappointment.

Now I just have to wait for that bonus check to arrive :)