I really like my VR50 Emerald iridium. They are very versatile but hard to find. Not sure why but Oakley doesnt really make them anymore. I think its there most versatile lens. I'm comfortable in all conditions with those.
The most common combo is probably Fire for sunny and hi yellow for darker days. The only issue with two lens is if the weather changes. Fire can be tough to see in if it gets dark. I would consider going with blue instead of fire because that will be a little better if the clouds come out a little.
In my opinion, I rather have a versatile lens(one of the vr50's) because weather does change sometimes and unless you carry the second lens with you, you might have some issues. Of course money is always a factor as well.
Hope that helps.