Looks like it's only epub.
If you never get it converted, you can reflow PDFs for accessibility, and then open them with foxit PDF reader. Then the text looks pretty readable. Foxit offers an option to force reflow but if you don't modify the PDF itself beforehand, usually all the words run together without spaces.
I wrote a little something on the subject as I had to wrestle with some large PDFs to get them to read smoothly on my phone. Try the very bottom of this page:
http://social.answers.microsoft.com/...1-677cde96b03a