New Alternator To Avoid
If you can find a different brand, it may the '78 amp' revised squareback will do the job.
I'd look into finding the matching regulator. It sounds like you've done other rewiring to handle the additional loads.
Have you seen the test data that Nacho got with a rebuilt '78 amp' alt? I've reposted it
here. You could use that to see roughly the max power output at various engine rpms if you know the pulley ratio.