Out of those options, I'd go with 70 cold and 50 light. 50 light is plenty of speed and more def is always good.
But what I think you should do is to make up for not being a pure str, go 90 ice/30 light. Your phy will increase tremendously with 90 ice. And if the Grass walk is to slow it's easy to buy typhoons when your getting 10x the money
