The font is in data\menu\menu.lgp but you can use modpath and aalis driver to make a new one instead that does not require menu.lgp
data\kernel\Window.bin is used for font spacing data.
data\field\Flevel.lgp is the normal dialogue
a file called mes inside data\wm\world_us is the world map dialogue.
ff7.exe has a lot of menu text.
data\kernel\kernel2.bin has item/menu related text.
Use touphScript for translation purposes. It can edit ALL ff7 text.
If you need a new font, you will have to create one using photo editing software, and place the correct files inside mods\ folder.
It is a very long task.