In order of ascending price:
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811119197
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811139008
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811119240
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811139013
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811133191
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811139012
-http://www.newegg.com/Product/Product.aspx?Item=N82E16811119245
It all comes down to preference. Looks, cooling, etc.