I think
Sal would be a good nickname for
Silas. Obviously
Cy works too, but I see your predicament. Although I don't think it's a big deal to spell it
Cy. That reminds me of a birth announcement from my area I saw. Cylus. Looked cool, until I realized it was probably supposed to be
Silas. I wonder if they had the
Cy probelm and that was their solution?
Silas Oscar does have too much S for me.
Silas Morgan is nice. Very Civil War
Era.