If I want to knit a scarf like [[https://d1a6t1943usoj7.cloudfront.net/v1/72d4fb3f-9e26-418a-9734-8b657f72583d/w756/superbulkybriochecowl_aiid925021.jpg this]] or [[https://cdnc.lystit.com/photos/2013/11/01/monki-grey-macy-super-chunky-knit-scarf-product-1-14595567-615221623.jpeg this]] what size needles do I need? 12mm? Also what sort of wool, where do I get it from and how much do I buy for an adult's scarf. I have been searching on the internet but not had much luck.