Newbie!

Hi, I'm just about to cast on my first monkey. I wanted to knit these as soon as I saw a friend knit one at our knit group, but after she tried them on and they were a bit tight I realised that the design isn't that stretchy and as I have pretty wide feet,the pattern was relegated to the 'one-day' pile . I then remembered that my best friend has her bday pretty soon (end of april) and loves hand-crafted things, so what better than a pair of monkey socks. She is tiny and although she has the same length feet as me (UK5) she has much thinner feet. I can't wait to delve into my sock yarn stash and find the perfect yarn for her. Is anyone finding particular yarns good or bad?