Store recommendation

I've seen that many people recommend bringing like tiny small hand towels to carry with you since they rarely have any paper towels in Japanese public restrooms. I don't have any at home so I thought I'd buy one in Japan – it actually makes a nice souvenir. What store would you recommend? Does like Don Quijote have these?

Another thing I'm gonna look for are these books you can use to collect stamps at shrines and temples. Would you know where they sell these?

Thanks a lot!