Nobody makes parts for Subarus like Subaru Tecnica International, Subaru's partner race division. Their short shifter for the Legacy is the only one that is good enough to be authorized by Subaru of Japan.
The STi short shifter is a complete shifter assembly, ready to bolt into your Legacy. It's preassembled, complete with a shorter shift lever and relocated pivot point for shorter shift throws. It's even pre-greased.