I have the Oakley assault pant in large. Its really baggy. I'm 5'9 for reference, and the thing is almost way to baggy. The picture is at a bad angle, the pants are much bigger and brighter than then look. But since your 6'0 i think XL would be really baggy, if you like baggy. But large would be a nice loose fit.
O and if you want to get any oakley product that they dont have shown on there website you need to call them and order by phone. The number to call them is 1.800.431.1439