Originally Posted by
Ex Pres
So while still a little bit of a guess, I'd start with a 113mm running a single ring.
That would not give the OP the 42mm chainline he needs for FG/SS, but he has it figured out:
"So...for a ~42mm chainline I would probably need a 103mm BB (112mm - 4.5 - 4.5)!"
-Bandera