I think the best way is to to hack the PSP complete collection to restore various aspects of the original (i.e. the difficulty).
Which is exactly what I did. I got it in pretty good shape, but the one thing I never did was locate the command data. One of the problems with the difficulty is that regular attacks and many spells were executed instantly or very quickly, which was not how the original one was. Interestingly, it is not because those values were changed in the GBA/PSP versions, it's instead because they modified the underlying framework for how speed values affected execution times.
I'd still really love to find this so I can finish my hack to make the definitive version of FFIV out of the Complete Collection.