Definitely something I'd love to have in this game. Actually I was searching for the suggestion section in this forum to post this when I realized you already did.
I think as job set keeps growing this makes more and more sense.

I don't want my MNK and SAM to look the same, neither by WAR, PLD and DRK... etc.
I like to play with every job but it is quite sad to have to decide on a specific look for all the jobs instead of being able to make them look different.