Custom right-click message WITH original download?

Hi All!

I shoot for a few groups at my kids school, and want to make the original files available at no cost to anyone who would want to download them, but prevent them from "right-clicking" and "saving-as" a lower res version.

I've set up the galleries to allow downloading of the original file - no problem here at all. What I would like to do is enable right-click protection with a custom message and still allow them to use the download button to get the original file. Ideally when they right click on the image the custom message would say something like, "If you would like to download the original file, click the download button located below the image."

Obviously I would like this message / setup to only apply to certain galleries, so other galleries which don't allow original download would still prevent the right-clickers.

Sorry if this is confusing - thanks again for your help!

Scott