static/noise from front audio port - z97 Killer

Noise problems like this can be very difficult to cure. I can only give you some suggestions that might help.

You already tried moving the front panel audio cable, which is smart. The power cables from the PSU can add noise. You know where the audio chip on your board is, on the left side below the IO panel connectors. Usually the eight pin CPU power cable is routed behind the mother board tray in that general area. You could try moving that cable away from the audio chip area on the board.

You mentioned grounding, which is smart too. I've noticed many PC cases will use painted (black) standoffs for the board, as well as painted (black) screws to use with the standoffs. How those are supposed to contact the ground points around the board's screw holes with a good connection makes no sense IMO. If you happen to be using standoffs and screws like that, changing at least a few of them to the standard brass unpainted standoffs with unpainted screws might help.

It's possible that the headphone jack in the case is either dirty or not making a solid connection with the headphone plug. Cleaning both might help, as well as checking the condition of the jack in the case.

If you can run the PC with the case side panels off, and experiment with the audio cable location while listening to the headphones, you might find a better location for that cable.

Usually a PC will have multiple audio sources, the boards Realtek audio on your board, the audio capability from a video card, and even the Intel audio from the Z97 chipset. You may be able to select a different source from the Sound option in Control Panel, which may not have a noise problem.

Be sure the audio cable connection to the board is pushed all the way in.