DAC for my Esoteric X-O3 SE??

What DAC will transform my Esoteric X-O3 SE to a level that will astound me? ...and what digital cable with it?
I have an X03SE going into an esoteric G25u upsampler/clock into a berkeley dac directly into amps and as good as the esoteric sounds by itself, this does make redbook cds sound beter.
Why would you want to use an external DAC with a player of this caliber? I would either move up the line and/or into one of their new "K" series players or look into separates (i.e. DAC paired with an Esoteric transport). However, I doubt either of these moves will "astound" you since the X-03SE is widely considered one of the best value players Esoteric ever made.