Is there an app that can convert a document (such as .doc, .ppt, etc) to PDF on the iPad?

This is what I want to do:

- Use a web browser to go to a class page
- Download a lecture (.ppt most likely, though maybe some .doc files)
- Convert the lecture to .pdf
- Open the new .pdf file
- Write notes (using a stylus) directly on the lecture slides
- Possibly add new pages
- Save the .pdf (including markup) and e-mail or upload to GoogleDocs so I can view it on a computer

I would like to do all of the above using my iPad. Does anyone have any suggestions on which apps to get? I'm leaning toward Notes Plus for general note-taking, however that app does not appear to have the ability to import .pdf files. My biggest concern is being able to convert lectures to .pdf files directly on the iPad. I don't want to get one of the office programs because they are a bit pricey and I would not really use them very often.

Thanks!