There are a couple of cotton/acrylic blends that might work: Berroco Weekend
or Berroco Captiva
or Reynolds Santana
You can also convert cm to inches in Google. Just type in xcm equals inches and there you go. (I always carry around 10cm=4inches and convert from there.) Good luck with your search and enjoy knitting the blanket. It'd be great to see a picture when it's finished.