Help me decide plz

I know definitely I want Raven to be my back up, but I am so confused on who I should main. I have narrowed it down to Catwoman and Harley. I really enjoy playing with them both but feel I need to narrow it down to one, so I can put full time into the character to be ready for tourneys. If you can all help me in deciding who you think would be the better choice and why? I really would appreciate your opinions on the matter.