FWIW, I don't think the short shifter kit is necessary. If you replace all the worn parts in the stock setup then you'll find that the shift you have is tight, precise and very direct.
The reason people think 944's have poor gearchanges is because, as Dave said, the pin in the gear lever wears out and takes the hoop at the end of the long shaft that runs back to the gearbox with it. If you replace the pin and install 968 bushes in the hoop in the long shaft, and make sure that there is no play in the pinch bolt that holds the shaft onto the shifter mechanism on top of the gearbox, then things will improve immeasurably. Another source of problems is the ball joints on the stay bar at the back of the shifter mechanism, and replacing these is another step in the right direction (although it's easier and cheaper to make a rose-jointed shaft using a go-kart steering tie rod - details here:
http://944foot2thefloor.blogspot.co.uk/ ... nkage.html ).
I had problems in all three of these areas on my S2. Less than £20 spent on some hardware and a couple of hours work and I now really doubt why anyone would want to fit a short shift kit to a 944.
Oli.