Orwell has excellent essays, available via this
Canadian website which collects all his work. Unfortunately he's a Life+50 author, so you'll have to do some sorting to weed out the few that will be PD according to US rules if you want to distribute.
To make nicely-formatted PDF versions of Wikipedia entries, the
PrinceXML people automatically include a stylesheet as part of their samples plus instructions on how to apply it to any entry of your choice. They are also free for non-commercial use, although they will put a small watermark on the first page of the generated file.