+1 paraneer. The power requirement is what I was eluding to and should have expanded on with my post. There are many quality speakers in the $500 price range, few of them will be at their best with 20 wpc. Too many have overstated sensitivity ratings and represent a greater load to a speaker than the impedance rating would indicate.
Making a short list of speakers that can be driven by your amp and then consulting with dealers, local and the aforementioned online ones, makes for a good approach.
