Your 600 crank should take almost any 130mm BCD ring without any problems. You can run into trouble sometimes with super cheap and nasty rings where the BCD isn't quite right, or the tabs for the mounting holes are too long, too short, not rounded enough, etc. For anything reasonably well made, you won't have any trouble.

On a triple crank, it's advantageous to have the middle ring designed for a triple, because it will have shifting pins and ramps to help the chain get up from the inner ring. An inner ring from a double will still fit, it just won't necessarily shift as well.