I'm only 24 eppisodes in but I think Kozue was perfect. She's always in a good mood. Kyoko, quite frankly gets too easily angry, kind of a lead-in to Akane's REALLY bad moods in Ranma 1/2, Ranma 1/2's got too many loose storylines and little plot!
Kozue's my type, maybe I think this due to my slight manic-depression. She'd be the perfect girl.