Well, they have two versions, a skirt and a full-length jumper -- I can't tell from just the little diagram there if the jumper version has a seam at the waist or not since the wraparound bit of the skirt covers up where a seam would be. Although even if it's cut in one long continuous piece, you could use the skirt pattern as a guide for where to chop it in half. ;)

And I'm sure you'd get your picture taken, probably even in groups since Avatar cosplay seems to be getting more and more popular.