Well, in part I am making a patch/mod of this game. The tools I use do not allow for changing the in game music(yet) due to the compression method used.
HOWEVER! I do like these 2 battle songs and the song called antidote, and its rare to see an FFT song remixed. I think adding some 8-bit sounds could make them sound really catchy. Of course I do not actually expect someone to do any of these much less all. I am simply linking them because they have a great range of sounds that I think could be used to remix wonderfully.
The songs:
Battle Theme 1
Antidote
Anticryptic