For your B&W 802 D3 speakers I would look for a used discontinued Classe Delta CAM 300 monoblock amps (class AB) or at least the Classe Delta CA-2300 stereo amp (class AB), which is a stereo version of the CAM 300 monoblock amps. These would be ideal for your 802 D3 and will sound really good on your B&W 802 D3. These Classe Delta series gears have been discontinued last year (2017) and today they can be found in used markets at discounted prices. The original retail price of the CAM 300 monoblocks were $11k/pair and the CA-2300 stereo amp was $7k and since they have been discontinued therefore you could find them used for cheaper. These Classe Delta series class AB amps are way better than the Classe Sigma class D amps.
Or you can possibly get a used pair of Classe Delta CAM 600 monoblock amps (class AB), which is top of the line of Classe Delta series amp to date. These CAM 600 were also discontinued last year and can be found in used markets at discounted price. They originally retailed for $14k/pair. These are awesome monoblock amps. I have these CAM 600 to drive my B&W 800 D3 front speakers in my dedicated home theater room. These are step up from the CAM 300 but will cost more. But the CAM 300 monoblock amps or even the CA-2300 stereo amp will be good enough for your 802 D3.
Other options will be the Parasound Halo JC1 monoblock amps and the McIntosh MC601 monoblock amps, which were recently discontinued this year and have been replaced by the MC611 monoblock amps. The new MC611 currently retails for $14k/pair. Either the Parasound JC1 or the MC601/MC611 will also pair well with your B&W 802 D3.
Other option will be the PS Audio BHK 300 monoblock amps. These are hybrid design with tube input stage and SS output stage.
But the Classe Delta series amps will be your best choice for your B&W 802 D3 since they were voiced together and thus will have best synergy with your speakers.