Loading PDFs or Images from URL into a CoverFlow view

I want to load PDFs or Images into a View, but when the source is an URL there might be connection lags, so I wonder what is the best approach when loading content (like magazines) into a Coverflow view in the iPhone?. (For Coverflow, something like this: http://apparentlo开发者_JS百科gic.com/openflow/ )

1. Is it ok to get a pdf file then obtain corresponding page images and show them in an appropriate resolution a Coverflow view? (Downloading the hole PDF might take long)
2. Or is better to download images as needed and then pass them to the Coverflow? (Although resolution might be a problem, hence maybe I wil need more than one image per page)
3. Would it be better to have a pdf file for every page?(So they can be rendered at any resolution and I don't have to download the hole file at once)

I hope you can give some advices on this.

Thanks in advance.

Just for the record: After some research I came up with images approach. They are the simpler, fastest, and reasonable good resolution. They can be loaded in 2 stages, regular resolution and better resolution for zooming, etc.