B&W 803D - Best amplifiers to drive them

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.

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.

On the tubey side - Conrad Johnson.

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!

Never heard the 803s but the 802ds are outstanding w the right amp!