Best practise - for Loading several images - external or library?

Hi
I am about to build an image slideshow.
I have a mainmovie.swf and a slideshow.swf. I will be loading my slideshow.swf into the mainmovie.swf. I have about 10 images to go into my slideshow.

Should I load the images externally via a Loader/ URL request, or add them to the library and export for AS?

Thanx appreciated