I have a hard time thinking of a less important spec than saddle rail material.
The distance between your ischeal tuberosities -- your "sit bones" -- is a fixed measurement. A bike saddle *must* support your weight at these points, and nowhere else.
Of the two saddles you mentioned, the one that better matches that measurement is the better choice. It's that simple. Now, it's also possible that neither saddle is a proper match and you should keep looking, but that's a different question.
RichC