I came up with a solution to these problems and designed (with the help of a web developer) an online 3D Gerber viewer that anyone can use. If you're not familiar with Gerber files, they are the files that layout software (like Eagle, Altium, etc) export for manufacturing. They describe everything pertinent about your board that will be required to actually create your PCB.
With the 3D Gerber Viewer, you'll be able to upload your Gerber files and zoom, pan, and rotate your board to have a realistic view of your PCB and all of the layers that it contains. You can use this viewer as you develop your board and also before you ship your final CAD files off to be manufactured.
Using the 3D Gerber Viewer is pretty straightforward, but the following steps will take you through the process and at the end, you'll have some images of your PCB that you can post somewhere or use to show off. More importantly, you'll be confident that your design is exactly what you had in mind!