B&K Sonata M200 + Polk Rti A9’s

Thank you everyone for the input but the sad outcome was that when I went to listen to them, there was a lot of hum in the background and I was afraid to take them since I don’t really know much about the issue. I offered to still buy them under the condition that I could try them at my house with my cables and speakers, and if that same humming was there, he’d take them back, he refused so I reluctantly passed.
now he’s offering me a Bryston 4B, which I know nothing about. 

The Bryston 4B would be a good choice if it is in good shape and working without issues! Yes it is an old amp but it is built like a tank and can drive anything! I have its 30 year old brother, the 3B - still going strong!

The m200s are also kind of old. My Nuforce STA 200 bettered them in every respect, even though the STA is less power and a single chassis. I gave them to a friend, who is going to do a complete rebuild. This was about a year ago, as the little Nuforce bettered many amplifiers in my collection, leading me to clean out my closets of equipment I was no longer using. In their day they were very good. No offense to anyone, just stating my experience ( I sold B & K way back in the day ). Enjoy ! MrD.