The user will get a simplified view of the end result that looks pretty and they can check a random smpling of data to make sure everything looks OK. I am doing this with css using lower resolution images. The other end spits out a high res PDF with many thousands of pages. I can see this taking up to an hour. So your suggestion is basically what I'm looking for.
I will take a look at the links and let you know my progess - I need to iron out a couple of image resize problems first.
Thanks for the fast input!