Used Which amp for B&W 802 Matrix series 3 around or under 1000?

In your case I think the Parasound A21 (used) would work very nicely.

Plinius has a warmer sound that will likely mate well with these speakers that can sound harsh if pushed in the wrong direction or with less-refined or cheaper electronics.  This might be a good match for those reasons…

https://www.usaudiomart.com/details/650000157-plinius-9100-with-audioquest-power-cable-priced-to-sell/
 

Best of luck.

Perreaux 2150B for around $900 on eBay. 340/680/920wpc@8/4/2ohms. Made in New Zealand like Plinius. A better amp for the money doesn't exist! I have one for use with power-hungry speakers like my DQ10's!

The Plinius weighs less than 37 lbs and is $1100.  The Perreaux weighs 68 lbs and costs less! Which do you think has a better power supply?

Perreaux made excellent SS gear! Why they are overlooked beats me!