As mentioned on the other 970 thread in this section: the only known company to release a native 970 waterblock at this time are watercool - a.k.a heatkiller.
Be sure to check their compatibility pdf prior to purchase, as it is for reference 970's only, to the best of my knowledge.
As for ekwb, they have been claiming that their 970 block is coming soon, for around 6 weeks now. Personally, I think that is just their way of saying "it's coming, but we don't know when. "