I'm a UK knitter and have used a lot of Rowan Yarns. They do indeed do a cotton blend, but also 100% cotton yarns in 4ply and dk. There are also some silk blends and the baby yarn range is very fine to produce thinner garments suitable for you lucky folk in warmer climes!
Here the summer has been a washout! Never mind more time to sit indoors and knit
Hope this helps and that you get lots of lovely bargains at your store!