Matt, there is a good reason many successful landscape shots do NOT have the sun in them. Usually the light values are too wide ranging to render both sun and subject(s).
This is the trouble you are having here, your choice is to either render the sun and sky or attempt to hold detail in the foreground have a blown out sun. Filters can help here but only up to a stop or two.
Your comments about your first shot indicate that you are already realising that a reflected light value can help render the scene. Why not go looking for something with a higher reflective light value (like water). This way you will narrow the gap between sky and reflected light. Filters may still be needed but you are then more likely to render the entire scene.
Your second shot demonstrates how a silhouette can show of an attractive sky. This is also a good way of rendering the foreground. Look for shapes with distinct and attractive outlines if trying this.
You can also wait until the sun goes down. Sounds counter-intuitive for a "sunset" shot however there is still plenty light just after it sets and the light values throughout your scene will be closer and easier to render. The longer exposures required usually give warmer, saturated colours which the viewer will understand as "sunset".
I hope these comments prove helpful and assist you in your preparations for your next outing.
