Speak to Daveb about a Porsche setup can run 312mm, 325mm or 330mm discs
the 330mm uses alfa brera discs and cost about £130 unlike the ECS R32 discs Bav is using which cost £500 + vat + shipping

Thought 323mm was the next step?
Patch - have you seen Tabs thread where he has fitted 996 rear brakes to his Bora thus retaining the 312mm disc?
I'd be tempted but running Anni wheels means I'd need 15mm spacers for the fronts!

Need 10mm spacers with anni wheels and 20mm with LCR calipers