Current alternator part number, 996.603.012.02 Bosch number 0 124 515 073. Now that is a 120 amp unit and apparently Porsche recommend the new 150 amp unit part number 997.603.012.07. I'll get cost tomorrow.
The voltage regulator part number is F 00M 145 350 and is available from Bosch distributors. I'll get costs tomorrow.
I know this doesn't help anyone just now, but it helps me collate all I need to help get prices tomorrow.