I fitted the original Porsche 997 Gearshifter and cables to mine. All I had to do was shorten the cables.
You can buy a billet shifter from California Motor Sports but the original plastic one hasn't let me down even with hard shifting
Hope this helps
Actually mine was a 996 shifter and yes is was a bit wide but i made it fit. I had a 996 GT3
cup car box first.It now has a 997GT3 with the original shifter. The detent to reverse does take a little effort but I got used to it. and the resistance helps not to select reverse when you really don't want it. I did find the cable adjustment was finicky, it took a few times to get it just right. That could be a good place to start. There is the correct Porsche tool to adjust the cables, which after much pleading and begging I borrowed from a local dealer.
But after a couple of attempts I got the hang of it without the tool.
Chris from Active Power modified and sent me a new transaxle shift lever. His modification lessened the reverse spring tension and that solved the issue I was having. The modified lever on the right (picture) worked and I now get reverse.
Mark, I forgot to mention the shifter I’m using was made by Chris and made to fit perfectly in aluminum. It is 4 inches wide and modified to use aftermarket cables. I can send you a picture if you want.