The Samurai outfit from the FFXI event does have a decent heavy-armor look... minus the chest and headpieces. Also, Papalymo's outfit in the Mog Station also has some heavier-armor bits on it, if I recall? I just forget if gloves and such are all one piece or separate parts. In both cases, though, you're straight limited to the colors of those items (red for Samurai and coppery-gold for Papalymo's stuff).
The biggest issue will likely be the chestpiece for that "armor" look.
The biggest issue will likely be the chestpiece for that "armor" look.