Automator AppleScript for a Disk Image

[applemaz]

Has anyone made or know where I can get an Automator AppleScript which prompts the user for a size in Megabytes and then creates a Disk Image?

What I am ultimately trying to do, is create an Automator script which will take all my iPhoto pictures and all my iTunes music and put it all on a single Disk Image.

The resulting image will be too big to burn on a DVD, so instead I'd like to save the image to an external FireWire drive.

As an aside, is it possible to just do an Automator script which takes my iTunes music and iPhoto pictures and regardless of size, burn them to whatever number of DVD's it would require to save the data? I don't know if during a burn it would be intelligent enough to split the files between DVD's and prompt for more when needed.