This is the best "Scratchpad" on the market:
https://www.amazon.com/Manhattan-GMAT-Si ... 0979017580 Almost exactly the same as test day booklet.
Also, I went to the testing center twice, and each time they had DIFFERENT ear plugs. They were significantly different. So I would advise you to get used to all types of earplugs if you believe this will be an issue for you. IF they are giving you a headache, try not to push them so far into your ears. They don't have to be deep in there to block out enough noise to help.
As far as the pen you receive, it is a very fine tip WET Erase pen. This means you can't just wipe it away with a tissue. If you press hard with your finger right after you put something down, you should be able to use ur finger as a little eraser. I would recommend that everyone purchases a scratch pad, b/c it is definitely different then a pen and paper. Please read my other tips here:
10-tips-to-improve-your-score-app-with-no-extra-studying-124393.html to get a leg up on your competition.