Looking for small monitor for small room

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

There are several candidates between $350 and $500 offered on  AG now to be considered, a PSB, a Wharfedale, a Triangle (new), several Monitor Audio. A great thing about buying small standmount speakers used is that, if bought at the right price, they can be resold fairly reasonably without much loss. Keep the original packaging. 

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.