First of all, we all know that nothing is 100% copy protected, but hear me out.
I am doing some volunteer work with a small charity, and they are creating a CD with PDF and JPG's on, and they will be selling these to help fund some of the charity.

They would like to where possible make these harder to copy, but still easy for a buyer to use. Obviously as a charity it needs to be very cheap / free, and fairly easy to produce, not mega volumes, but maybe 5 at a time.

I found something called SecurDisc, but it can only copy protect a pdf, and only does it on a DVD, and these needs to be a CD.

Any suggestions would be much appreciated.

Copy protection tends to be pretty weak.  You can just DD the disc and you end up with another disc with the same copy protection software.

It's not quite what you asked, but what about encrypting the CD?   This way, anyone can freely copy the disc, but would need a key to decrypt the contents.