Air to airs?

Most of the time my Kazuya gets destroyed in an air to air duel. In SF4 not much of combo opportunities are available, but the juggling opportunities in this game makes it hard not to receive a heavy combo after losing in air. So I think know what his best air to air move is. 99% I use either HK for fron attaks or MK for cross ups, but never gambled and experimented with other normals. If you know a good air to air, please share. is gdlk