Used Speaker in the 15k range

If you're going to upgrade everything then take a look at Kii 3, Dutch and Dutch 8c,  Genelec 8361A. 

MAGICO,Vimberg or Rockport jump on a pair ASAP!!

If you poke around a bit you can get a pair of JBL M2s for right around there.  I would have a hard time believing you could get a more accurate, better sounding pair of full range speakers for the same price.  I looked at a lot of different speakers thinking the M2s were out of my price range.  Then I did some digging.  It's worth asking.

Check the other thread that asks the same question.HELLO!!

I purchased (new) a pair of Legacy Whisper XDS with the Wavelet Pre-amp/processor and love them.

I see that there are several posted for sale here on audiogon.