That cooler on the leadtek isn’t worth shouting about tbh. Also Asus GT's generally have better overclocking gpu's than the leadteks.
Id go for the Asus card and pop a cheap cheap Arctic Cooling Accelero S1, this cooler on its own can passively cool a gt so if you add a couple of fans it becomes a killer air cooler! which would totally nail both cooling solutions that come with either card.
If your more bothered about warranty than overclocking, probably best you go with the leadtek