Yeah, now I remember trying to decide between the two back in the day. Ultimately I went with the Saturn version because EGM (are they still around) declared that version to be better visually.
As for the Action-Replay-Plus, I have the 4meg version. I have to pop open the system and exchange the first disc with the second one, and then restart the system from the Action-Replay. You should be able to boot up directly into Phase 6, the first section of the second disc.
Man, it's been years since I've played this game and on my 57" it's spectacular!