Woot, just completed the Stalwart Defender set. The set has 4 style pieces: chest, legs, waist, and feet. You can superimpose your emblem on the chest. The Stalwart Defender style is inspired by the New-52 Superman costume, and the style pieces can be gotten from Promethium Lockboxes with the start of Game Update 26 introduced on 28-05-13. The style pieces are tradeable, so you might want to keep an eye on the broker for them.
Stalwart Defender style - Front, Back, and Side views