S6e or S8e. Spendor does two way designs better than three way. The S8 is a really wonderful speaker.
Recently a new owner of he S8e. I agree with the other posters it's basically a $3000 speaker that sounds like a $12,000 speaker. This speaker should meet your needs. They look like box speakers but sure don't sound like it. Very open and throws a huge deep 3-D soundstage which is finely layered. Can resolve ambient information from front to back and it's articulate. But most importantly it renders instruments and voices with a natural tone.
I'm very happy with my S8e's in a similarly sized room. The S5e's that I tried first didn't quite cut it. I agree that the midrange and upper bass are phenominal. I didn't try the S6e's. I'm really amazed at how well these speakers do with rock, although I generally listen to jazz and classical.
My Cary V12r sounded very nice, but they really seem to like more power. I'm very pleased with the Musical Fidelity KW500 integrated amp that I'm currently using. I would expect that your system would work well.