Which battery for a 997 Turbo?

[AMG Merc]

Apologies as I'm sure this has been done to death already but my local reasonably priced Pork dealer (great bunch of guys) wants £240 (and a well known OPC wants £375!) to supply and fit (and we all know they don't make batteries anyway, right?!).

I can't seem to find what spec battery Pork put on the car originally. Was it a 75ah or an 80ah? I have a loaded motor so wouldn't mind the extra power. I'm looking at a Bosch S4 80 amp (99961108020X) at under £100 (I can handle the complex fitting and resetting of the PASM, etc. myself!).

Any thoughts please?

[AMG Merc]

Fitted an uprated battery myself in the end - Bosch S5010 Silver Plus 85amp at £102 with 5 years warranty. Local indy dealer wanted £240 fitted and main Pork centre - th lots of shinly marble floor tiles - wanted £370. As for their comments about resetting the PASM , etc. turn the wheel one way, then t'other, then drive in a straight line for 10 yards - job done