Speakers for Rega Brio R and/or Nad 326bee

I have both integrated amps and I'm looking for a small monitor. Have the Silverline Minuets and wanting to see if anyone thought the Rega RS1 , Dali Zensor 1, Usher 520S or other speaker might be better with the Brio or Nad. My tastes are with mid-range, sound stage, female vocalists, resolution and detail. Since there are so few dealers near me I've purchased several speakers and Minuets and Paradigm mini monitors sound best, but Paradigms are too large. I think I would like the Rogers LS3/5a or Harbeth P3 sound but they are too expensive for a second system. My room is 10x 11 and budget is under $600 used. Your thoughts are appreciated.
I had Silverline Minuets and preferred them to Rega R1s (not the RS1s). Better integrated sound and the R1s were too sharp on top (although the new tweeter in the RS is supposed to be better). I think they're hard to beat for the money.
I nominate the Quad 12L2 or 12L Classic (newest designation for same speaker). About 8"x13.3", 87 dB (pretty good for a minimonitor), well engineered, beautifully made, and very engaging sonic presentation. They list at around $1100/pair, but the link offers a demo pair for $899, and if you look around enough, you should be able to find some in your budget. There are lots of them on ebay.uk at or below your price range, but of course, that's before shipping.
The Quad 11 L2 is very similar to the 12L2, but with a smaller woofer in a smaller cabinet. There is a pair on A-gon within your price range. I have no affiliation with the seller or the sale. There is also a pair of active biamped 12L2s listed there.
The Rega RS1's work and sound great with the Brio-R (never heard them with the NAD).

Another option that matches up with the Brio-R is the Tannoy DC4 (or DC6 if you stretch your budget a bit).

***Rega and Tannoy dealer disclaimer***
Dana 630i are in your price range new and they are very nice little speakers.

Epos monitors will get you the great midrange you want for a fraction of the price of the Harbeths. I believe the new line of Epic standmounters are well reviewed. You can check them out here: Epos Epic

I think they would make a good match to those two lil amps. Sam Tellig tried them with the Brio here (toward the end of the review): Epos Review