Novice needs help: Sonos 50w amp and ? speakers

Hi,
I have a Sonos system and I'm looking for a great a pair of monitor type speakers to be driven by the 50w Sonos internal amp. I have a medium size room and need wood cabinets. Price range up to 3k (but flexible).

So I believe I need easy to drive speakers? Some ideas from reading a little:

Harbeth (not sure which model)
Paradigm S2
?

Does anyone have recommendations?
Thanks in advance,
Doug