well, i don't know about a GUI character replace menu, but it would be possible to do that pick and match system with folders with pre-made character replacements, open a character folder such as 'cloud', then in the list will be all sorts of people like Hojo, Sephy normal, sephy final, Barret, tifa, other bad guys, zack, junk like that. it would be kinda big to have every replacement tho, so why not simply the 'favourites'? IE:already playable people, Shinra and the Sephy's? (as well as infamous bosses like Dyne)