Alternator info

I was wondering how many of you guys run the 93mm Nipondenso alternators? The next question I have is what amperage ratings are they. I'm running a Meziere water pump and a 2300 CFM electric fan. The 40 amp alternator Im running will not keep up.
I see they make this alternator in 60 and 70 amp rating, has anyone tried one and do you like them? Where would you recommend buying one?
Thanks...