Aperture/iPhoto Slideshows

Hi guys,

I work with video editing and whenever I need to show some pictures I tend to use the Aperture/iPhoto Slideshows. My questions are:

- Besides the Apple themes, are there any other available theme?

- How can I change a slide layout? For example, I want to define the number of pictures and the slide type (one picture above the other or besides).

Thanks
Rafael