In theory, we already have "redesigned" versions of what the GC leaders wear; it's the Hunt GC gear.

The Elite Adder Caster set is a redesign of Kan-E-Senna's dress. (Kan-E-Senna is a white mage)
The Elite Storm DPS set is a redesign of Merlwyb's coat. (Merlwyb is a damage dealer gunner)
The Elite Flame Tank set is a redesign of Raubhan's armor. (Raubhan is a gladiator)

It's a way to imply that the Elite of each GC is what closest approaches the power of each respective leader. I don't think we can have the exact outfit of theirs though, as that would take away the special look out of them. I think it's also why the Elite sets are not dyable.