"Another question: is ~60 watts sufficient"?
That will be very dependent on your room volume, listening distance, and how loud you play your music. In some case 60 might be just fine.
I have found that these dynaudios thrive on power. My Luxman is 120 watts/8 ohms, my room 18 x 12 x 9. I have enough power to play loud and clear.
When I had my Wyred for Sound Sti-500 (250/channel) I had plenty, but did not get the richness, dynaudios are capable of.
I tried a 75 watt tube amp (ARC 75si) and did not get good sound.