Ah yeah ok.
You can use 325mm with spacers on the carrier.
Problem is you need a 325mm disc with 5 x 100 PCD.
Only option with that is Custom bells/Discs i think.
Cupra R discs maybe an option at 323mm, less spacing on carrier.
Daveb does the lines for porsche calipers, he's your man for brakes ! He's on UK-MKIVS, dunno about here.
For hassles sake you could use 312mm Discs and some good compound pads - Ferodo ds2500's, EBC yellows. Disc size doesn't mean a massive thing.