Hanne Yarn Substitutions

I am seriously thinking about making another Mermaid. Do any of you know of a substitute yarn? I went to the Hanne website and it appears that the yarn is only sold in kits. I can buy yarn based on the gauge but have no idea how much to get. I know how many balls I got with my kit but didn’t weigh the balls to even begin to figure the yardage. Anyone have thoughts?