From what I can see, it looks like you've got 3 connection options:
1) Coaxial Digital. 2) Optical Digital 3) Analogue
Any of the 3 ways will be compatible, you may want to determine the best option by listening first. Just compare options 1 or 2 with 3, since the difference between 1 & 2 should be insignificant (if even audible at all)
The sound quality wiil depend on which of your two products has the best internal DAC (Digital to analogue converter)
Options 1 & 2 will be going through the DAC in the soundbar, wheras option 3 will be using the CD player's own DAC.
Option 3 would require twin RCA plug to 3.5mm stereo jack plug lead (or adaptor)