Complete all Arena missions, then use the following combinations with the "Customize Armor" option:

ARMOR - COMBINATION
Fleet - Helm of Swiftness, Leather Jerkin, Bone Shaffron, Leather Drape, Leather Crupper
Guardian - Chain Coif, Cuirass of Heroes, Chain Shaffron, Faceted Peytral, Chain Crupper
Reaver - Leather Coif, Cuirass of Heroes, Doom Shaffron, Chain Peytral, Leather Crupper
Savage - Leather Coif, Leather Jerkin, Chain Shaffron, Chain Peytral, Chain Crupper
Stalker - Leather Coif, Leather Jerkin, Rock Shaffron, Rock Peytral, Whiptail Crupper
Totem - Wood Helm, Wood Breastplate, Doom Shaffron, Faceted Peytral, Bone Crupper