GGH Viamala and the Union Square Poncho

I want to knit the Union Square Poncho from Weekend Knits. I have the book on order and know that it takes 12 skeins of GGH Viamala. Has anyone used this before or done this pattern? I was wondering if there is a decent sub for the Viamala. This is the first poncho I have seen that I have actually wanted to knit for myself. I am hoping to have it done for next fall… so I had better get started! Ha ha. :happydance:

Any advice or suggestions would be appreciated!