I have heard the PrimaLuna amps with ProAc speakers, and it is a nice combo. You list some of their newer models here though, which I am not familiar with. I have a Dialogue 2 integrated and like it very much. I have heard it and a few of the older models on the ProAc Studio 140's, which I think have a bit more efficiency than the ones you list, but I am not certain of this.