Scratch pad???

If you don't mind spending some money, then Manhattan's test booklet is a worthwhile purchase. In my view, it is exactly the same as the actual test booklet used during the GMAT. Veritas Prep also has a noteboard, but I am not familiar with this particular product. I could be wrong, but it seems that the Veritas logo is on each page. If so, then that could be a distraction.

You mentioned some options (laminated paper is another one), but the use of test-like notepads can be safely limited to practice test sessions. For question practice (from the OG or Jeff Sackmann, for example), regular loose leaf or notebook paper would suffice. In fact, that might be better. With regular paper, you can review any mistakes. With an erasable booklet, however, there is the chance that you would run out of space and erase some of your work. I must emphasize, though, that this comparison only applies to question practice. For CATs, a test booklet is superior.

Also, here are some related links:

• manhattan-gmat-test-simulation-booklet-w-dry-erase-marker-94084.html
• using-a-notebook-versus-test-simulation-booklet-and-marker-90620.html
• gmat-working-pad-simulation-booklet-66689.html

Hope this helps!