What you want for a sneaker for flat feet is a shoe that supports the arch, but does not make the arch too high which will cause fatigue to the foot. You want shoe that will contour to the specific shape of your foot, to help support the arch. Below I have listed what I believe to be the best Saucony Shoes for people with flat feet:
Saucony Triumph 10 Running Shoe– This shoe features an sockliner built from EVA. I happen to think that EVA is one of the best materials you can have for someone with flat feet. What EVA does is mold to the contour of your foot and at the same time provide solid arch support.
Saucony Kinvara– There is that material in this shoe EVA, for this shoe it is a light weight EVA. So if you are a serious runner this might be the shoe to get since it is superior to the Triumph.
Saucony Hurricane 15 running shoe– One of the major causes of flat feet is pronation. This shoe was specifically made for the overpronater. This shoe features heel locking technology which helps reduce overpronation. So if your flat foot is biomechanical in nature this is probably the shoe to look at.