[Porsche9]

Is this a forever car? If it is and you have the funds put in a rebuilt motor with the appropriate mods so it will withstand years of track duty.

If not go the used motor route and just be patient until the right one comes along. By the time 03/04 rolled around they weren't selling like hotcakes anymore plus it's just a two year window so there aren't too many around.

Or, sell the 03 as a roller and find yourself a 00 - 02 S. Plenty of them around at reasonable prices.

Or, if you have the time and money have Jake Raby build you a motor to your needs and know you'll have one of the best if not the best motor that money can buy for your car.

Good luck.