How different are the shapes? It looks to me as if you are willing to scale the type and images, which means you can consider simply placing the pages of the original file (either as .indd or PDF) into a new file. This can be automated using Scott Zanelli's script: InDesignSecrets » Blog Archive » Zanelli Releases MultiPageImporter for Importing both PDF and INDD Files
hmmm........ the differences are
the placement of the text on the page
size of the font
all the text and images are linked
Will I still be able to automate this along with copying the text?
As the line heights are increased which automatically adds space between the the paragraphs which would lead into adding more pages to the doc.
So before I go to the link, will I be able to do this?
That method only works if you want to have an exact, scaled copy of the file at a different size. Seems like I probably misunderstood and that's not waht you want, but you can run the script and see what you get.
The advantage of this method is there's only one file to edit, then you just update the links. But you might want to take a look at Alterante Layouts and Linked Stories in CS6 as well.