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.