Buying from Amazon as seller will get you the 960GB.
Release date as per Amazon Japan is 20th April
Please use my referral link if you like this deal: http://amzn.to/10HiiEC
If the shortened url isnt working, try the unshortened one https://www.amazon.co.uk/dp/B00BQ8RHJ2/ref=as_li_ss_til?tag=…
Choose Amazon.co.uk as seller from list (last seller) and click "add to basket" (button on the far right)
Sure, Amazon usually dispatches things earlier, but that's potentially a very long time to wait. :)