Probably the best version to go after the difficulty: a softer one (which I'm kinda sure it's still slightly harder than GBA/PSP/PR) or the actual NES original one. Without the "select carefully your opponents otherwise you fail a turn" that was more an archaic thing than a design choice, let's be real.

Real problem about this and all the PS1 versions of classics Final Fantasy(s) are the aggravating loadings. This one defends itself a little bit but you can still feel them.