Undercity's reputation can be added to the copy of the uniform, and you can also buy a 14 bag and a blue cloak for worship. The quartermaster selling uniforms walked along the inner ring of undercity (that is, the platform where the innkeeper stood), and there was an NPC riding a horse.

If it's the shirt of the silver-white alliance, it's in the BL tent of the silver-white alliance. That needs a warrior badge.