I can only speak English but I want to be able to play final mix. Is it better for me to just play the english version or is better to get the final mix version and get a patch? This isn't for current games but for future ones because I don't want to miss out anymore since I'm from the US.

if theres a choice between getting the japanese version imported along with a japanese PS2 and get the patch, or get the english version, the choice is obvious. and in the future there is a possibility that they could get released for outside of japan (it's a slim chance, but still possible)