Well, from what I've gathered, the pronunciations Spoony listed are the correct ones, having either been confirmed by Dissidia (yes, it's Zi-DAHN/Zi-DON) or the Japanese romanizations (so no EYE-ko).

IMO, it's important that these stay consistent. If half the people present mispronounced the name of a person present, it would be incredibly distracting.

One thing I guess could be a good idea for making sure people pronounce the names the way you intend them too without worrying that they won't read your transcriptions right - post some vocaroos. I could alternatively type them out in IPA, but I doubt that effort would end up being appreciated