ive compared stock a9l and a9p binaries in BE and a9p has slightly more agressive fuel and spark, biggest difference is lower load spark is higher in the a9p to help the automatic car on the low end. i also noticed a9p has slightly leaner target AFRs in the higher loads, should make more power.
if your not tuning the car, i'd get the a9p, if you are tuning the car it doesnt matter which one you get. you can change anything when tuning so it doesnt matter.