I have the gladiator plate on two of my warriors. All the gladiator sets are available to everyone, except boots and belt, which are no longer in the game.
A good site for transmog is wowroleplaygear.com. They list sets and try to give alternatives when certain pieces aren't available. And download the Mogit addon. --- This is my new sig. It sucks compared to my old one because apparently gfaqs mods have never seen cleavage before. GG.