What I did find is the Loft Task Lamp from West Elm. It has the same black powder coated iron shade and thin black iron rod base. The lamps are pretty similar in style and for $74.99 (+ 20% off) I'm really happy with my West Elm purchase.
For reference, this is what the bedside previously looked like. Those sconces served their purpose for awhile (they're battery operated so it was a cinch to take them down) but they looked tiny when paired with the new, much larger, nightstands.