Julie Madison would be interesting . I think she was in the serials and last played by Elle Macpherson in the film that didn't happen
. She would fit into the Bruce Wayne, Lex Luthor, world of socialites putting their name behind the rebuilding of Metropolis.
I actually wouldn't mind if the love interest turned out to be a woman who's had a past with both Bruce and Lex. I'd prefer that triangle to a Lois , Clark, and Bruce triangle.