Nad M3? Need amp for Vandersteen 3 $3,000 budget

McCormack Amps are a good match.

I agree, McCormack.

I have those speakers and have used Bryston 3B-ST and Quicksilver V4 Tube Mono Blocks. I have recently settled on Red Dragon M-500 Class D Mono Block amps. The others were good in their own ways but overall I prefer the Red Dragons. Clean, powerful, great extension in treble and bass. Very reasonably priced.
Another option is finding a used Audio Research 100.2 or 150.2 which also were quite nice. Good luck.

For rock music, I will suggest an used Theta Dreadnaught 5ch, disable the center channel and use the other four to bi-amp the Vandy 3A.

Ayre Acoustics uses Vandy speakers to "voice" their amps during design/development, so they are a natural and often-used pairing. Ayre V-5XE amps are available secondhand for $3K.