Re. appropriate shoes: VivoBarefoot Neo Airmesh: 4 mm sole (+ 2 mm insole cuhioning or not, your choice), zero heel-toe differential, very flexible, with enough room in the toe box for your toes to spread out, and can be worn with or without socks, as you prefer. I really like the Neos. The Evos are more funky-looking, very slightly narrower, and some people find they rub if worn without socks (I've not worn them because I need the Neos for the toe box width). They also do Neo Trail (2 mm sole + 4 mm lugs) which is what I'll be wearing for NDW50 next month.
Depending on size, you may find them relatively cheap on Sportshoes.com.
xine is right about the importance of changing running style: short stride, landing fore/midfoot then the heel touches down, foot landing under you not in front, high cadence (I run about 190 strides/minute).