B. Search this specific forum for "grinder build" and you will find a few good examples of homemade grinders. I think if you study the pics and plans available you can easily put a fine grinder together.
What makes a 2x72 grinder a good grinder is:
-power: 1.5-3hp should be the motor range....bigger the better
-ease of changing the setup (I.e., tooling arm slots, easy and quick to use belt tensioning systems)
-variability of speed
-rigidity: Make it a stout machine with heavy duty parts