On FF6, The GBA version is great, and cheap. Slightly better, overall, due to some added dialog that was left out of the original. The PSX version is aweful, try to avoid that if at all possible.
And, oh, I'll just state that not everyone thinks Chrono Cross is the best thing since sliced bread, I thought it was terrible and a disgrace to the Chrono Trigger name. Where CT excelled in being light-hearted and entertaining, CC becomes cynical, dark, serious, and ultimately: extremely pretentious. Just my POV, but I know others share it too.
Oh, and do pick up a Wii (or at the very least, a GameCube) if you get the chance, there's a lot of really GREAT RPGs and Adventure games out for it, and many in the works.
reguardless of what you may think CC's gameplay is solid.