My NAD 7100 can run 2 pair of speakers at the same time n/p.
I assume you are purchasing NAD components, of which I have the C series (see profile)
I like the setup with my H3's, but I feel the horns are a bit bright for my liking and I am constantly adjusting treble on my NAD pre. Might be the SS amp, or might just be "the NAD sound" I used to have a ST-70 but didnt buy a quality pre. My mistake.
The Heresy 3 is a great speaker, but needs a subwoofer. Adding a ksw12 sub to my setup improved it tremendously. However, my next move will be a nicer sub, either an SVS pc-plus or a HSU. After that, Ill probably kick my Pro-Ject Debut TT up a notch and get a Music Hall with a nicer cart, platter and arm.
I listen to classic rock, pop, and some rap. Overall very happy so far. NAD makes nice gear. Good luck!