I would seriously consider implementing WP and using the original theme, it will be so much easier if you plan to add more content in the future.
It will take about an hour max to learn the basics of WP and will save you so much time in the future. If your hosting has fantastico it literally takes 5 minutes to set it up. Drop me a pm if you want to have a look around the back end of a WP site
If you are dead set against this then consider something like
Perch which is a CMS that you can add to an existing html site.
Good luck with the site whichever way you decide to go