What are you wanting to use the extra power for?

The 70 - 115 makes 70 at ~ 1,800 alt RPM and 115 at ~ 6500 RPM ( don't quote me on the RPM, I don't have the actual specs in front of me. )

The 60 - 120 makes less at "idle" and more up top.

This style of alt is a Bosch IFIR ( internal Fan Internal Regulator ) and is used on other cars, ( SAAB , Audi VW and others. You might be able to get larger internals and swap into your case but that will require much research and trial.

There was also a Valeo alt that I don't know much about in terms of power, near as {I can tell they are a compatible with the Bosch units.