Red2618,
Just run stock brakes with fresh fluid. They are really quite good and will never overheat on single lap AX runs.
For reference:
All the Boxster Spec Race cars run stock brakes to good effect. They run continuous laps from 20 min sprints to 1hr enduros no problem.
My car runs stock brakes in AX, DE, and TT with around 20 track days/yr and a handful of AX events. Brakes might be our greatest advantage in these cars.