Mike the mix its like I said, nobody here can answer your question with a general YES or NO.
I am sure it depends on the html pages you have if they can be displayed correctly or not.
You can transfer your .pdf files via ftp to any locations you want.
Link that you generate in the CMS are the same like in normal .html files.
Why not simply give it a try? Install the hack and work with it.
Include some of your pages and check if its working for you or not.
Bringing content from one system to another does also mean you have to spend time and that you have to do work.
There is no automatic process that does it for you. The only automatic process that I know in this area is called "manpower" and that does mean that you have to pay someone else doing it for you