Pretend that picture is cut into 3 parts. A$$ is the homescreen as you can see. That wallpaper is all butt lol. In all honesty thats all you are going to get from it. I would look for a picture that is a full body shot centered then you get the girl mainly on the home screen. Panning left or right when you change pages.

Great source of wallpaper fit for cropping and resizing. wallbase.net

 

This isn't exactly 960x800 but its the type of pic that will be centered better.

 

When you select the photo for the wallpaper re you given a box over the image? If so you simply use two fingers and expand the box to include the whole picture. Hope this helps!