I have no experience with many of the speaker models mentioned here. However, I do have some experience with NAD amps but not the M33 in particular. NAD amps mate very well with PSB speakers since they are, or were, sister companies. I've heard more expensive speakers that didn't pair as well with NAD. Something in the Imagine T line may fit your tastes.
Other brands mentioned here may be a better choice but I'm just offering my opinion. Of course, the best option is to audition your amp with prospective speakers but often that's not possible. Good luck in your search.
Other brands mentioned here may be a better choice but I'm just offering my opinion. Of course, the best option is to audition your amp with prospective speakers but often that's not possible. Good luck in your search.