On Wall Speaker choices for secondary system

I'm looking for wall mountable speakers for secondary system in the family room under $500 pair used.

I'll probably used with 35-50W NAD stereo receiver.

Any advice?
NHT SB2's ... now replaced by the NHT Classic 2. Were $400 new, typically discounted to $300. Worth tracking down. Pair exceptionally well with NAD.

Regards, Rich