I have found the exact kind of notebook for which I've been wishing! It is called Scrubby Notebook and I ordered it from good ol' Amazon. Mine is 8" x 10," and it also comes in a smaller size.
There are about twenty pages in the notebook, and they are all a shiny plastic material, so the markings can just be rubbed off! It's like a little portable dry erase board! Did I mention that I love this!?!
It comes with a black erasable marker and a large rubber band, which holds the pen securely in the spiral when the book is closed for storage. These pen markings don't rub off onto the side of my hand when I'm using them.
I also ordered a pack of the pens in different colors.
The pens all have an eraser on the end. It is a fiber piece, and seems a little like old fashioned carpet pads.
There are instructions for cleaning off markings that have been left there for a long time (basically use rubbing alcohol). I taped this page inside the back cover so it will always be with the notebook. I know myself well enough to anticipate losing something like this!