Used amp recommendation

Monitor Audio GS60 Speakers.  Aragon 18K Pre Amp.  Cambridge Audio Azur 640C-B V2 CD.  Need new amp.  Used in $1500 range.  Suggestions?  Thanks.  
Assuming you want to stick with SS amps, then you should put Bryston on your "possibles" list. They are fine amps, have a transferrable 20-year warranty so you are covered should the amp need repair, and they provide unparalled customer service.
My suggestion also would be to get the "matching" Aragon 4004, 8008ST, or 8008BB.

Speaking of Acurus, I have owned 12 Acurus amps and none have ever had any issues at all.  All dead quiet.