Ive just got some insoles with a stiff bottom that goes almost to the ball of the foot. I'm going to try them in my running shoes to see if it is stiff enough to help with the pain and numbness I sometimes get. I may need something stiffer over a larger area though. I have been using MKS RMX pedals but may try some with a larger surface on them. I'm not ready to clipless and give in to Big Pedal just yet.
I had a pair of New Balance shoes for tennis that had a stiffer sole than my running shoes. Some companies make mountain bike shoes that I think are for platform pedals, they may be something to try.