Replacement amp for B&K ST-2140

I use 23 year old B&W Matrix 804 speakers and B&K Sonata MC-101 preamp. Which new amp would work best with this equipment?
What is your budget and are you willing to purchase used? Your preamp is getting along in years, are you considering an future upgrade there?
It has been many years since I looked into the newer amps and preamps. The ATI 1202 amp B model is available for $611 shipped, and that company was the last owner of B&K so would have had the benefit of their knowledge for future production. However, they don't make preamps. I would rather buy new and as I am 70 next year, this might be my last audio purchase. Would like to spend less than $1000 for the amp, $1000 for the preamp when the time comes, or should I consider an excellent integrated amp now for under $2000? So I need advice as well as recommendations.

The Sony ES cd player, Audioquest and Monster connects are also 23 years old but there is no indication of problems. To be honest, I have not played music all that often in recent years and use Youtube on the computer a lot, but want to focus on the stereo system more from now on.
I see from the Sonata thread that your amp is fine. Happy Thanksgiving!

If you were to move beyond you B&K separates I would be inclined to buy an Integrated at your budget. Many good ones available.
I'd consider a used Classe' amp.
Thanks all. Happy Thanksgiving Day.
I can vouch for ATI amps. I used one in my office system for several years. I think ATI is under appreciated. They offer tremendous value. Build quality is excellent, good warranty, built in the USA and the sound driving M&K professional monitors (4 ohm) was very pleasing to my ears.