@KingBetts: Sorry but this “No Sidebar, Full Width” layout is only there in Catch Evolution Pro theme and it will automatically take larger image size of 1190px by 500px. But I see that you are using Catch Evolution Free version and there you don’t have this option.
But if you can customize it, then it’s bit technical and you can accomplish this in your free version as well. Sorry, I will only be able to guide you in this. You first need to create Child Theme. Then copy content.php file in your child theme and then edit the following code with your image size.
<?php the_post_thumbnail( $imagesize ); ?>