Looking for small monitor for small room

I took a chance on these, for my office system, similar size room as yours.

I use them with a self-powered sub, they are terrific, true bookshelf size, no ports

https://reverb.com/item/4594417-b-w-dm-100-i-speakers

https://speakerholic.blogspot.com/2015/04/b-dm100i-speakers.html

I have a perfect triangle, with the monitor in the center of my desk, wonderful imaging as center is phantom anyway.

Keep an eye on the Audiogon marketplace. $350 used can purchase a $700 speaker that is not to old.

What if I went to $500 or. What would you recommend?

The NAD 3130 is a 30wpc amplifier I believe. If I am correct you will need a speaker that is not to difficult to drive. With the small room, I would be more concern with impedance aspect than sensitivity. That said, I would look for a speaker not being lower than 87dB sensitive.

The Silverline Minuets suggested by Soix would be a good choice.