Use something like Nikola or Pelican with [favourite python template system here] to hit the sweet spot between hand-coding/frameworking and CMS. You can adjust any part of the look, feel and templating easily and you can enable customers to have a very easy/cheap way to get the site up, running and maintainable.
Because it is a static website there is no security maintenance needed. You don't have to be a programmer to work with a lot of these static site generators and the time investment to learn them is quite low in my experience.
Also, you can always just drop a PHP script (or embed snippets that are compiled in) with the static site to do any dynamic stuff you may need.