Where to buy 16GBx2 DDR4 kits for Z170?

[bbbubbleboy]

I'd like to start out with 32GB in a 16GBx2 configuration for the Z170 system I'm planning in order to easily upgrade to 64GB later, say 2 years from now, by adding another such kit.

It seems such kits can not (yet) be bought???

 

[bbbubbleboy]

That's a DDR3 kit (and also ECC whereas Z170 requires non-ECC as far as I understand)