I will need to replace the alternator, so I am considering the options. I want to upgrade to a modern high output alternator. Has anyone done this and can offer advice? I really don't care about the appearance, I just want it to work well and be reliable for many miles to come.

69 2+2, air conditioning, 4 speed manual trans.

I was looking at one on JC Whitney web site Powermaster, but I really am not sure if it will fit? Is this a universal application?