Small Photoshop Job - Jewellery

Our new website design needs a banner on the home page. The banner will simply be a light blue box (with rounded corners) on a white background. The banner will be constructed using a an html table, of fixed height (200px). On the left side, there will be text. For example: "Our diamonds are great!". On the right side, the will be a picture of an engagement ring (see attached file). The picture of the engagement ring is 350px x 350px, therefore, the picture will "stick out" from the light blue box, on both the top and the bottom. An example of this would be the screen sticking out at the bottom of the banner at [login to view URL] Therefore, the picture's background needs to either be: a) entirely transparent OR b) have a white background for the first 75 lines, a light blue background for the next 200 lines and white for the last 75 lines. I have tried myself to make the the background transparent, but my photoshop/magic wand skills are lacking. You are also free to enhance the look of the diamond/entire ring in any way.