Advice on Integrated Receiver

B&W 800 series will be very nice - D2 or D3.  
They sound engaging and will draw you in. 804 or 803 for that size room most likely is all you need. However, they like power and require careful matching when it comes to the upstream components. Can’t have anything upstream that’s on the brighter side and or that emphasizes the presence region. When I had the N803s I had them paired with Pass Labs X250.5 and Audio Research tube preamp.
I think you’re pretty much looking at an overhaul.

If you want to go the integrated route, Pass Int-250 (would be my first choice) or Hegel H390, Hegel H590 or the Luxman 509 (slightly underpowered for the B&Ws IMO).

As for the phono stage, I like Sutherland for sound and flexibility. Even the bottom of the line KC Vibe MkIi is excellent.

Just my $0.05 of course, you will get other suggestions so start compiling the info.

@bound4h 

your speakers dip below 4 ohm and might be straining your amp at moderate volume levels- for example the impedance dips below 4 ohms in the bass frequencies between 100 to 200 Hz which means those frequencies take twice as much amplifier power to produce the same volume level.  

With a 5K budget I would recommend a better, more robust amplifier as well as a better more dynamic phono preamp than the Mani which is an underwhelming sounding unit.  

The Parasound Hint 6 is a very smooth, dynamic amplifier capable of very high sound quality and has enough grunt (240 watts at 4-ohms, your speaker's demanding frequencies).  

For the phono preamp you usually get more up beat, dynamic sound when you have a more robust power supply.  The Lehmann Audio Black Cube SEII is a very dynamic robust phono preamp that has a separate outboard linear power supply and is a giant killing value at it's price.  

A new robust amp and new dynamic phono preamp will give you a huge upgrade and be suitable for your speakers which are more than capable with the right supporting system. 

@avanti1960 

@audphile1 

Any experience with the Rega Aria?  I have the P6 and an all-analog phone preamp made by the same company as my TT seems like a smart move?  The price is in line with the Lehmann.

The Aria is good but the Lehmann offers a better value. The power supply in the Lehmann is superior and I made good use of the bass rumble filters on it that tightened up the bass response by not wasting energy on sub sonic frequencies.

https://www.lehmannaudio.com/phono-stages/black-cube-se-ii.html 

@bound4h Check out the Belles Aria Signature integrated amp (not a ‘reciever’) Might get you close to your budget IIRC, the non Signature model certainly would.