Posts displayed on a Page.

Hi – before posting here I’ve tried a number of methods to try and achieve my desired result, all of which have failed. I’ve also combed the support forum, and can’t see anything here either.
I understand that my request may be above and beyond the call of duty, but I am after a way of listing posts on a standard page, rather than a category page. The reason I want to do this is that I need to add content to the page before the listed posts, including an embedded map, and the category page is too limited to achieve this.
I have tried a number of tutorials for creating custom page templates which are supposed to work like this, but have had zero luck.
As an example, here is the category page for the hillfort monuments of Berkshire.
But what I’d like is something a little more like this, which is a standard post – Caesar’s Camp.
So in short, is there a non-maddening way to produce a custom page template that you can add content to like a normal page, but under which you can list the posts from a specific category?