The GT/CS hood scoop is nice I love it on my car, the Roush is nice it's just a bit larger wider then the GT/CS. If you want a sick looking hood scoop get the one off the 2007 Shelby GT, those are sick!
The Shelby GT scoop is pop rivited on and looks rather tacky in my opinion. I like the GT/CS and put one on my car as I feel like it is more to the 65/66 Shelby than any other. (The original scoop was not pop riveted and is the weakest point of the Shelby Gt's imop, love them otherwise and test drove a black one.) There is a pic in my garage out the front so you can see the view from the front seat.
Beware--it is a pain when you wash the car! It drips forever.