FWIW, although I agree with Onhwy61 in general, your post doesn't really help me in understanding your needs. You ask for more warmth but I have found that when a lot of folks do that they are in fact confusing warmth (as described by Onhwy61) and the need for a reduction in upper mid range glare most often caused by electronics, especially a lot of CDP's, speakers, and room placement and acoustic's.
In looking at your list of components I would rule out the Vandies as being a contributor to your problem - they are not inherently bright or cool speakers. Your amps are not known for being warm - to the contrary, but whether you need new ones or not is yet to be determined. (On that subject, if the amps are a problem, I would highly recommend that you not spend the money for two amps for these speakers, just get a better amp and run them full range).
I can't help you with the NAD stuff - I'm not familar with it. But I'm always suspicious of CD sources aas being a particular source of the problems your post suggests.
If you are trying to eliminate brightness this can also be changed by room placement, toe in, and 1st reflection points. Best to rule out set up as a source of your problem before replacing anything.
