* Doing both PDF and html. It is *not* easy to have two completely separate formats for the same document. I am telling you this from personal experience having made the attempt and given up. You're looking at more than double the effort, which may not make intuitive sense, but any work made toward producing a PDF is all but wasted making an html document and vice-versa. And obviously any last minute change made in one document has to be made in the other. In my case, I realized there were at least three valid spellings for the word "legionnaire" in MS Word at the time. All of this stuff may sound like a task that just takes 5 minutes, but that 5 minutes invariably turns into 15 or 20 minutes and you're going to have dozens of them for any document of respectable size.
Errr... that's because you're doing it wrong. Why on earth would you have two separate sources instead of one that is translated into the final formats? Maintaining separate formats for a single document is not a difficult task.