Well, I would do that, but after talking with Justin Pawlak (Pro drifter who drives an FC3S) a short throw shifter seems to put more wear on the transmission, and seeing that I have 140K on mine, I dont want to risk it.
Also, just as a follow up on this, I found the bushing, a company called MMR makes it:
http://mmr-direct.com/catalog1/RX7FC/index.htm
EDIT: Just to clear something up, Justin, to me, is considered a "Pro" because he actually competes, has sponsors, and is way more involved in drifting than just your average joe, even through he was in the "Amature class" in Formula D or whatever.