Mini Monitors under $500 used

I have a small room 10x10x8 that Im using as a den. Have a Nad 326bee and Marantz 6250 cd, what would you recommend for speakers? Detail, sound stage, and resolution are important to me.
thank you for answering
Why don't you check out the new Emotiva Airmotiv 4's or 5's and use your NAD as a preamp to drive the speakers as they have built in amps. They use ribbon tweeters and are supposed to sound fantastic for the $$.
The Hyperion Monitors miss very little music and are outstandind for their quickness and clarity. Not fatiguing either.
Triangle Titus would be a slam dunk.

These cross over fairly high at about 5khz compared to many monitors and have fantastic coherency in addition to all the traits you seek in spades. Perfect for a smaller room.
I'm currently listening to a pair of Usher S-520s. Pretty darn good for the money. Real lookers also.
anyone pair the 326 with a pr of Paradigm mini monitors? wonder if the PSB speakers or Paradigm mate better.