Bad Alternator?

Started hearing a new noise from my engine about a week ago (sound was intermittent, didn't always make the noise). Sounded kind of like a coffee grinder running in my engine bay. Noise was definitely coming from the right side of the engine (from in car perspective). I noticed the alternator belt was slightly loose, so I tightened it; the sound actually got worse and became more consistent . Today, I finally had some time to take a look at what is going on. I wanted to remove the alternator belt to see if the sound would go away, this way, I could narrow down the noise as something that is external and not inside the engine. Well, went to start the car, nothing--battery is completely dead. Tried to hook up my battery charger, but it would not charge. Battery is 6 years old btw.

I'm thinking I have a bad alternator, and possibly a bad battery now. I'm going to head down to autozone to have my battery checked, then have my alternator tested.

Do the symptoms I described above fit with having a bad alternator, if so, where do you recommend finding a replacement? I checked autozone, but all of the alternators listed are re-manufactured or premium reman, what's the difference between re-manufactured and premium reman? Thanks

1968 Dodge Dart 270
273, 2bbl engine