Here is the thing. Oakleys are not much better than any other half decent sunnies. I've had laods of oakleys some good ones, some that i dont like that much. I had a pair of Flak or Falks or somthing last year, could not find them at the start of the season, so i got a pair of "Sunwise" from the shop at the county ground, 22 quid or somthing. Now i have them both side by side i can see that the sunwise ones are a copy of the oakleys, but i honestly find them MUCH better. Better fit, feel lighter, len's dont steam up, which the oakley tend to.
Long and short of it i'd get down the shop and try some on, even if you them buy them on line... small differances can make a big impact on how you get on with them.
Bonus tip, if like me you feild at slip, test them out in "the postion" as some are better than others, on some the top rim can get in the line of sight.