What type of alternator do these sharks have?

I am about to buy a high amp alternator but my question is whats the difference between the 1 wire alternator and I guess the ones that came with these (sorry don't know the technical term for the type)?

I am thinking of buying the "Mr Amp" alternator for my 79. It produces 65 amps at idle which is what I need to power the spal fans I have. The stock alternator can barely charge the battery when its idling. So this is going to be a necessary upgrade, a high amp alternator that is. In either case I will be converting to EFI and adding a lot of ther electronics in the future so this is going to pay off in the long run.

My question is how hard is it to convert from the "3 wire" which is what these things came with right? to a "1 wire"?

Will the conversion from 3 wire to 1 wire be necessary for my future plans? And should I just do the conversion now?

Does anybody have any other suggestions for other alternators that produce high amps at idle?

Thanks for the help

Frank