Warrior Kara is probably the most horribly dated design in the whole series to me. She just overflows with 1990s vibes. I'm not sure what would be good for her. The sci-fi barbarian look might be good, though personally I'd want more of an emphasis on the sci-fi than the barbarian. The Xena look has become a bit of cliche to me.
The design you suggest for the other Kara seems good. It does provide a royal feel and is certainly battle worthy than a long, flowing dress.