What is best for the speakers JBL Everest 6600? Mark Levinson 53 or Boulder 2060?

Hi friends! I have speakers JBL Everest 6600. I use  with tham  integrated amplifier Mark Levinson number 585. I want to buy the best amplifier. I stopped   Mark Levinson 53 or Boulder 2060 second hand. I want to know your opinion. I heard the sound of Mark Levinson 53 whith JBL Everest 6600,   but never heard whith Boulder. It is interesting to know your opinion. Best wishes. Vladimir.