Every foot is different; why not go to a sporting goods store that carries Nike and other reputable brands and describe your needs to a salesman? Trying on shoes is the time-honored and sensible way of buying footwear.

Athletic shoes today are complicated; there is not only weight, but cushioning, size of toe box, cant, materials used to make the soles, issues of space for orthotics or heel cups, and thickness of socks you wear.

PS. Many athletic shoes are now designed also for high, low or normal arches and various kinds of pronation, supination, or normal foot-hitting-pavement.

Nike’s latest product is Nike Light After years of selling shoes with all kinds of padding, their latest pitch is that walking barefoot is the most healthy form of walking and they have designed a shoe that tries to feel like walking barefoot. I have been considering going to a store to see what they are like.

I would second @gailcalled‘s suggestion of going into a store and trying out a few different brands. My feet are wide and Nikes always feel tight and uncomfortable on them while Asics feel more accommodating (and just as light). After trying on shoes, you can always cross-check prices online to get a good deal.