The de Capos are a very easy load for any amp and reasonably sensitive, as well. At various times, I used Cary 300b monos, an Atmasphere S30, and a big ARC VT 130SE, as well as a SS Krell KSA 50s. All worked well, but each sounded a bit differerent - so a lot of it will be personal taste. The Krell seemed the least successful match as the pairing went a bit "dark" and dynamics were less dramatic. No clue why, but that was my impression. The ARC worked well, but I used the other amps more often, so that suggests I preferred the Carys and the Atmasphere. I was voting with my time - you could say.
The S-30 that I owned was from early production and had limited bass capability on other speakers that I used it with, but it mated very nicely with the de Capos. Same for the little Carys, a very good match. IME, lowish powered exotics seemed to be quite happy with these speakers even though these amps had been rather picky about speakers overall.
I now own Prima Luna monos and I suspect that these would be a good combo, but that's only a guess since these amps never overlapped the de Capos in my system. FWIW.