Depending upon your room and taste, you might also consider JM Lab or Rockport. I'm not sure about compatibility of the other tube amps you mentioned with the Wilsons, but Atma-Spheres have been used very successfully with them, as have Lamm. I agree with Aceto's comment about Watt Puppy forward compatibility, as 5.1 -> 6 -> 7 has required a new purchase each time instead of being able to retrofit.
Brian
Brian