Unless you are adding high amp electronics like subs or e-fans the stock unit will do. Otherwise a competent rebuild shop can bump the output to almost any reasonable number. With the higher output more heat is generated and this lowers the alternator's lifespan. Also higher output units carry more inertia so it requires more engine power to spin up and increases the belts tendency to slip. The alt charge wire to the battery should be new or upgraded as well.
After replacing my year old 130amp unit and speaking to my rebuilder it finally hit me. The stock underbelly pan has a neat cut out just ahead of the alt for cooling. My aftermarket pan didn't include this feature so I added one of my own.
