Buttons loading and unloading Movie Clips

I have created a page with a scrolling buttons bar of thumbnail images. I would like to have large versions of the thumbnails load on the stage when a button is active and disappear when another button is made active.

I can achieve this by loading a swf for the large image into a movie clip on the stage. But I am wondering if there is a way to do this using a movie clip for the large image so that I can have an intro and outro animation as the large clip appears and disappears from the stage.

Also, is it more efficient to be loading a large number of swfs or stick with movie clips?

Any help anyone can provide would be great.

:jail: