04/05 6MT shift linkage bushing purchase link
06 6MT shift linkage bushing purchase link
I don't know which one fits the LGT or 06 WRX though, so you'll have to PM Turn in Concepts. I posted these links as, as a Vendor, it's not kosher for TiC to do so in this forum and it is rather hard to find those link on their site. *hint, hint....TiC*
As to the dimensional differences:
Normal shifter has a wider width at the pivot point
STi/SPT short throw shifter has a narrower width at the pivot point
This is why TiC has two unique pivot bushing sets and it's important to know what you have as to what to order. That's a broad generalization of course and your BEST course of action is to PM them with your year/model and get the right advice the first time.