Customising an XML Image Gallery

I have found a great gallery that I would like my XML Gallery tutorial to mirror - http://www.theage.com.au/flash/soccer/slideshow.html

There are a couple of things I can’t get to work.

1. Having the different sized images load from the center of the screen rather than the top left corner of the empty movie clip
2. Having pause and play buttons that can stop and start the presentation

Most of the other functions I am not too concerned about.

Can anyone provide some direction?

Cheers