I change my stance so I feel comfortable (relative to the situation) and don't have a concrete answer. I feel more natural in my south paw stance but my technique is more stable with my left hand forward. To be honest, I like a nice axe-kick for a lead followed by an appropriate combo (assuming I haven't been beat up by then). To me though, a lead is intentionally exposing a weakness to encourage them to exploit it. Like chess. With my right leg forward I like a quick "ginger fist" to the bridge of the nose, lead hook to the back of the jaw, or straight jab to the face. With the left leg I prefer a solid boxing stance and more defense. I like the jab-cross combo, my hooks and uppercuts. If someone throws a flurry during sparring I like to use a shoulder to push them out of my infighting range and try to hit them on the way out with a one solid shot rather than a combo. The problem with my right leg forward is that I only use my lead limbs, don't use a lot of combo's and try to stay out of range.