If your template is PDF you can use the community commons actions OverlayPdfDocument. This way if you create one PDF which is the empty stationary you can overlay all the Mendix created pages with this page. And indeed in the appstore you will find other sollutions to do this.
If you need to achieve more complicated styling you could try with some of the app store modules for document generation e.g. https://appstore.home.mendix.com/link/app/114043/