Ok and since we all figured it out so fast... lol
I figure I will let everyone else know:
Shell speeds and camera shake are contained here:
CannonShellPhase.entity
CannonShellPsi.entity
CannonShellTech.entity
Cost, Armor, Anti-Matter, Hull restore, etc... are contained here:
PLANETMODULE_PHASEORBITALCANNON.entity
PLANETMODULE_PSIORBITALCANNON.entity
PLANETMODULE_TECHORBITALCANNON.entity
To modify the buffs (like Annatar said)
AbilityPhaseOrbitalCannon.entity
AbilityPsiOrbitalCannon.entity
AbilityTechOrbitalCannon.entity
BuffPhaseOrbitalCannon.entity
BuffPsiOrbitalCannon.entity
BuffTechOrbitalCannon.entity
BuffCannonShellPhaseOnShips.entity
BuffCannonShellPhaseOnStructures.entity
BuffCannonShellPsi.entity
BuffCannonShellPsiOnShips.entity
BuffCannonShellTech.entity
That should help anyone else.