Six years have passed (can't believe its been six years, time flies!) from my original response. Moved up the Shindo preamp food chain from a Monbrison to a Masseto to my current Vosne Romanee. And amp-wise, the Audio Research components have been gently stored in favor of a Shindo Montille to a Cortese F2a then the current Lafon WE300B monoblocks. The Valencia's in this pairing have more than enough drive for me (all genres but with an emphasis on jazz, R&B, classical and women's vocals). But for a period, I did run a McCormack DNA-1 SS amp with the Valencia's for grins and they responded very well too. If I hadn't happily tumbled down (up?) the Shindo "rabbit hole", the McCormack would have sufficed in my setup (it too is presently in storage).
I have read reviews on a couple of the First Watt amps that put out 5w or 10w per channel and maybe one day I'll try those out.
Best wishes on your quest!