Tony ,
The nad amps like the 3020 are great but they have an artificially warm sound with plenty of midrange emphasis.This means that they probably best suit open, neutral sounding speakers.[cold sounding even]
Also they are not very powerful so benefit from quite efficient speakers.
Paper coned speakers might work better than heavily damped cones like plastic or even doped paper.
How about Robertson Audio speakers?.A local company that makes excellent products.
Also if you can find some ESS speakers [old or new] with the Heil ribbons, these are a superb match with the nad 3020 series amps-they have a understated midrange that compliments the NADs perfectly.