Hi,
Are you using portal engine or ASPX development model? The mention about Visual studio confuses me.
In portal engine, you can create a
custom page template. You will assign your layout to this page template and also, place the web parts you want to have on this page template (e.g. you will create a dummy page using this page template in content tree and then on Design tab you will add the web parts). Now, if you will use this page template for the documents - it will be always the same with the same layout and web parts.
Best regards,
Juraj Ondrus