Need advice on CMS: use DB or modify existing files

I really need some advice concering Content Management functionality, because I really need to know how to continue.

Let me describe the website a bit first to get a better idea:
/ (root)
Startpage
/category1/
/category2/
/category3/
Each category is filled with pages
/include/asp/
Contains header,footer which are included in each page
/include/js/
Contains external javascript files which are e.g. included for menu in header
/include/css/
Contains all external CSS files which are included in the header

Basically every page is based upon the same concept. I use this concept for every page. The concept uses SSI includes for the header and footer. By doing this I keep all pages small.

So it's more like I use a "template" for each page I'm going to make. Such "template"/concept got the basic structure, some HTML comments where the main contents should go, which title to change, BUT... as can be seen the contents is not entirely separated from structure or template. The template got a function as "startfile".

But now I need to make some sort of Content Management System and I'm wondering what to do?

It seems I only got one option left: open a file with FileSystemObject and retrieve the to-be-managed content and making it identifiable with e.g. HTML comments like: <!-- begin text --> and <!-- end text -->

Or should I SERIOUSLY consider the following:
1) Put all contents in a DB
2) Use one template
3) Use a CMS with contents from DB
4a) Possibly create "static" files by merging DB and template

It would mean that I have the contents in a DB and in those generated files, unless I let those files retrieve their contents on a constant basis from the DB, but if those files don't change that much it puts a load on the DB.

So 4b sounds maybe a bit too DB exhausting:
4b) Generate the displayed pages with DB and template for each user.

It just seems a bit TOO difficult maybe to be loading those pages and filtering the contents for management. It may offer some room though for "exceptional" pages which got a different kind of contents. But since most pages are probably "default" I might be better of with DB/CMS option.

Please I really need some advice here. As you can see I'm nearly convinced that this DB/CMS thingy is THE way to go eventhough it might mean that I got contents at 2 locations (DB and files).

Thanks, any piece of advice... recommendation, thoughts. ALL is welcome really. And I do need this advice. So far I've only made most of the structure and there's hardly any contents yet. That will follow soon. I wish to have things ready beforehand.