Try partsexpress.com. They have several binding posts. Since yours are broke, etc, you should be able to pass a non-Klipsch pair through the holes where the originals went. You might be able to clip the solder as close enough to the old terminal point to get a crimp ring on the new post end without having to resort to the soldering next to that crossover circuit board.
In the kingdom of the blind, the one eyed man is still just the bus driver....