Grog,
Backcountry.com has full-zip Shaks in black in stock in S,M and L. They have a 20% off coupon right now too.

I have not really been a big Icebreaker fan as most of their stuff seems to be made in China, and does not have flat-lock seams. But I wanted a merino hoody, so I got the Icebreaker conquest hoody. It seems very well made and is full-zip with mostly flat-sewn seams. It is very soft and warm. I had tried the Ibex shak hoody but found it too scratchy and didn't fit right. Guess I'll have to try more Icebreaker.