I just installed the SPT/Sti (they are the same part) Short shifter..
I got it from Carlsen Subaru for about 236$. First off the kit. You get the whole shifter assembly. This includes the shift lever, the rubber flange mounting gasket, and two linkages. One going from the lever to shift the tranny and another connecting to a rod that is attached to a stationary bracket (has a eurathane bushing at the end). NOTE: There are NO instructions!! You will need an instruction manual of some sort. OR.. You can look at how the shifter is assembled yourself or look into the i-club website.
Installation.. I took a "year" trying to figure out how to take out the pin that holds the universal shifting linkage together while under the car. Eventually figured out that the all of the parts except for the shift lever itself was different. The dimensions were identical! Therefore, I spent probably 170 bucks too many for the shifter kit!!
Followed the instructions on the web and it went in fine.
Performance.. This shifter has MUCH less slop (IMHO) than the stock one. This is since the moment arm changes. The position of the shift lever bushing is about 1" higher. This gives the shifter more leverage. The shifts are a lot more crisper and quicker.
Conclusion.. It seems that Subaru is ripping off customers with parts that we don't need. Plus it lead me to do a lot of work that was unneccesary. Still, I was able to quickly install the shifter in one afternoon and the performance of the shifter has impressed me.
Out of a scale of 1-10, I give it a 6.5 .
Note: if anybody has found a use for these extra parts other than spare parts, please inform me!