From what it sounds like, you could just use the blog itself. This tutorial – https://appfinite.com/tutorials/how-to-create-multiple-portfolios/ would work for the blog and regular posts as well. Just make sure you have the featured image enabled in your Genesis Theme Settings.
You could set up specific blog posts to show on certain pages (like the tutorial). Otherwise you would need to edit the css of the portfolio posts to be full width.