Luxman 509X, 590AXII, or Gryphon Diablo 300 for B&W 802d3

I own the Luxman 590AXII and it powers Harbeth 30.2’s which have an 87db Sensitivity (yours are 90 I see) with no problem. I can get well past 95db loudness when cranking it. There has been some discussion about the fact that although Luxman says it’s pure class A 30 watts into 8 ohms, 45 at 4 Ohms, third party measurements have also claimed it does switch into Class A/B above 30 and outputs 90 watts in A/B. Perhaps a dealer will let you try the 590 and switch it out to the 507 if you feel it’s necessary?

I don’t worry about it however, the 590 has a warm, but clean sound, it is clear without being sterile or bright. Great headphone and MM/MC preamp built in, I personally like the tone controls, and for me it drives my speaker fine.

I have never owned B&W speakers, so I can't tell you if it's a good match with them. I have heard PASS, Hegel and other integrated amps and they all sound great. Just a personal choice at that point. Hope this helps.

I own the B&W 803 D3. Before they arrived, I owned the Luxman  L-509X. Something was missing big time compared to what I had heard these speakers many times at at least three dealers and a friend. So I switched to another integrated amp, my current T+A PA 3100 HV. Everything came back to life the moment I switched it on. Couldn’t be happier.

The Pass equipment is truly wonderful I'm using a 250.8 with magnepan 3.7i never a problem and rarely leaves class A. Reno HiFi will let you demo in home. There's also the used option which I took based on reviews

I had the 802D3 for a few years in my system and had a few different high end amp. My feeling is that the highs and mids will be wonderful with any of the amps you mention, but bass will be a challenge in any reasonably large room. The bass will be tight (probably more with the Gryphon) but it will never have that huge impact. If your a bass person, like myself, you might need to consider a pair of subs. 

+1, @thyname

@jeffreyw

T+A Integrated’s are pretty awesome, ultra detailed and plenty of grunt in lower octaves. I used to own B&W 800D2’s and you can’t fully appreciate B&W’s (especially the 800 or 802’s) until you feed them with an amp that’s stable down to 2ohms load.