Does it REALLY have to be a male hero?
No, no. I specifically said hero/heroine. I know I didn't write any suggestions to Lois reacting to a female hero, and I apologize for not fully seeding your imagination.
Actually, it might be fun to have Wonder Woman (or another female hero) come on the scene and instead of having Lois reacting out of jealousy, as per the norm, but her giving up her idolatry of Superman in exchange for becoming Wonder Woman's greatest supporter and fan. Go, female empowerment! What would Clark think about this change?