I am looking for reasons "for-and-against" using PHP for this project, it has a header, footer and sidebar. We don't think we will make too many changes and our webmaster here does not know PHP, but the coder is saying it is better to use it. Opinions please with explanations? thanks in advance
Well, you're not listing any specifics. Is this just a static site for which you want a separate header / footer / sidebar file for easy maintenance? If so, even the simple server side include (apache) could work just fine. If not, you'll have to list what it is the site does. PHP is just fine for simple sites like these.
At a guess I'd go with yes. If you have any site with a basic template around content, it makes sense to use PHP
Use the PHP, which will allow for each change in the future and integration of other features if your site requires it.