Let's see: very efficient speakers, nice pre amp, and you need a good amp?
Have you considered a Burson?
I have the integrated version for my Tonians (not as efficient as yours-the Tonians are 95db) and it sounds wonderful. I believe the amp is around 90 watts per channel, class AB, and it has the cleanest sound in my limited experience. Not antiseptic or analytical but clean, rich, full, and engaging with detail aplenty and not at the expense of tone, body and texture. Great for all kinds of music.