One note on the OEM bars. To me, they are the ones that look the best, but If I had to do it again, I'll go with the Yakima Whispbar or the Thule AeroBlade Edge bars. They are twice the price, but they have many advantages over the OEM Like, you being able to lock them and having more space to mount accessories.
There's something scary about being able to get these bars off with just a screw driver. I know in the end if somebody wants something, he/she is going to get it but the lack of any lock or theft prevention is unnerving. It also depends of where you live/park often I guess.
Also, with the OEM bars, the amount of cargo is hindered by the parts that clamps to the roof rail. They are big chunky and are not straight. If you need to mount more than one thing on your roof other than a bike tray, I'll recommend going with the square or round bars as you are gonna have more real state to work with.
Just a thought.