There's a lot of converters out there, primarily aimed at fetching text from a layered pdf. Most of them are crap (God knows how many I've tried), but if your document are really text and a few images (but no foreground layer with an image of a scanned page), you might get a very decent result from
Lighten PDF-to-Word. There's a free version, that only converts to word and clean text, which should suffice for the purpose at hand.
It's no direct conversion to epub or Kindle, but it yields nicely formatted Word docx (depending on the source, of course). And from Word to epub to Kindle is much easier than from PDF - there are various tools for the word --> epub conversion, e.g. Atlantis Word Processor, TextMaker Wordprocessor, Calibre conversion, Toxaris' plugin for word - etc. - search the forums
- and the Kindle Previewer can convert the epub afaik (I'm not a Kindle user, though).
Oh, and by the way: I am not and have never been in any way affiliated or associated with Lighten.
Regards,
Kim