I used part of a 100 gram skein of hand spun 2 ply Merino and Angora yarn. (This yarn isn’t quite a chunky weight, when I look at the ply is looks like 2 double knitting yarns plied together, perhaps just slightly thinner, if that gives you a better idea of the thickness so you can substitute).
Just check the hat on your head for size though while you are knitting. The handspun is 9-10 wraps per inch.
5.5 mm circular needles for knitting with the Magic Loop technique.