I found B&W match very welll with the Krell FPB amps.
I previously owned the 803D - it still a great easy to listen loudspeaker. Re your questions:
1. auditioned 802D a few times - more open midrange, bigger bass not as well controlled as 803D. So for 802D recommend choosing an amplifier with reputation for tight bass control.
2. visual expectation for checking drivers in perfect order. Kevlar midrange tends to go darker and more orange as ages, but accelerated by exposure to sun. Check for consistent veneer colour for cherry wood. Obviously listen to loudspeakers - make sure you like what you hear, but understand dependency on gear driving the loudspeaker.
3. I drove the 803D with 60W amplifier - quality and good current capability more important than watts. At simplistic level, solid state amps that double watts from 8 to 4 to 2 ohms indicates good current capability.
A substantial difference from 803d to 802d. If you can afford it buy the 802. I've owned and enjoyed the 803d for many years. I used a mcintosh 252 amp and c45 preamplifier. When I got the upgrade itch, went to the 802 diamond, and a 402 amp (same pre). I couldn't be happier. The sound and soundstage was a huge improvement. I use the 4 ohm tap on the amp bi wired with great results. I wish you luck on your search!
The nautilus top gives a superior touchable image of instruments and voices. Also the sound is more natural sounding. They only weak point of the B&W are there crossovers. They are poor in depth. I owned the 802N and the 800S for over 8 years of time. I listend to the 800D, but I did not go for it. I wanted to go to a higher level for the absolute sound. Then depth and a wide stage is a pre. B&W misses this important part, so I stopped with B&W. Musical Fidelity is a good option for your speakers. Wenn you have more money Pass Labs is a great match.
Kelpie, I owned the 803d for about 2 years and loved them. They do like lots of power though. I originally had a McIntosh MC352 connected to them and it sounded great. I bought a second MC352 and biamped them and they sounded even better. I finally purchased MC601 mono blocks and they sounded like a brand new speaker. The bass that I didn't know was there came right out.
I liked the 803d's so much that I deceided to move up to the 802D2's, I think they are worth the upgrade, though both are very nice speakers.
When I went to the dealer to purchase the 802D2's the dealer had a pair of PMC EB1i's there to demo against. There was no contest to the sound I heard coming out of the EB1i's. I liked the PMC's so much I purchased them on the spot. I have since purchase another pair of speakers but love them all. They all sounded great. It was only when I A & B'd them next to each other that I really had a preference.
I upgraded from a used pair of 704's that I really liked to a used pair of 803d's a year ago and then quickly began to ask the same question. I was using the Rotel 1070 seperates set that were a perfect fit for the 704's, but found myself wanting more. After looking around and becoming confused with all of the options, I settled on a used Accuphase E-450 integrated and could not be happier. The sound is smooth, detailed at any volume, never induces fatigue compared with previous equipment and I can't imagine the speakers sounding much better. They simply come to life. Have matched it with the Oppo BDP 105, Apple TV for streaming and TV, and an Accuphase t-1100 fm tuner and am going to retire with more music options then I'll ever need. I'm off the gerbil wheel for good, or so my wife tells me.
The size of your room will influence the amp. I have the 803d and use a Classe CA2200. Previously used a Krell KAV2250, but the Classe is a bit warmer. Pre is Krell KSL. Also used a VTL 5.5 which was very good. Room size is 16' x 23'. Generally speaking, you'll need some good quality/good current power as noted in previous post. Hope this helps some.
I own a pair of 803 Diamonds and drive them with X 4 NCORE NC400 mono blocks. They certainly love power and woke up very noticeably in their current configuration compared to my previous amp (Pass X250).
I auditioned the 802Diamond at the same time and actually all but made up my mind that I was going to get the 802's before arrival of the demo but after the audition I didn't feel there was a $5K difference between the two speakers.
So instead, I spent that $5K building X 4 mono blocks to fully power the 803 Diamonds to their max potential. Even before doing this, using the Pass X250 amp on the 803's they still were plenty close enough in SQ to the 802 to not loose any sleep over.
I have no regrets in my decision.
While I agree that McIntosh, Musical Fidelity and Pass Labs are good choices, like
Saackesc, I recommend Accuphase amps for B&W speakers from the 800 series.
Accuphase is IMO a significant step up from the brands mentioned above, but it
is also more expensive.
Regarding the 803D vs. 802D issue, 802D is without a doubt the superior
speaker. If you have the space for the 802D and can afford it go for it. Buying
the cheaper model is never cheaper in the long run.