Just out of interest, why would you prefer 1080's? aha

You could get this;
[ Register or Signin to view external links. ]
CPU is pretty balls to the walls unnecessary. 8C/16T monster.

I'd probably suggest something like this instead though;
[ Register or Signin to view external links. ]
6C/12T CPU should be plenty. Still gives you room to upgrade to a 5960x/6900k, or 6950x if you really want to in the future. Or even a variety of Xeon's, if you'd prefer something with more threads than 16 and have a few thousand to drop on a CPU. Grab a 1TB/2TB HDD as well if you need more than 1TB of storage, and the 256GB 950 PRO. GTX 1080 isn't really worth the premium over the 1070 IMO, but with the 5820k build, you could get 2x1080s in there. However, these EVGA 1070s are in stock, and will perform pretty close to a 1080.

I'd personally get a pair of these 1070's instead;
[ Register or Signin to view external links. ]
but stock is iffy for the Asus 1070s. The EVGA 1070s are in stock, perform just as well and are $30 cheaper.

If you do decide to go with 1080s instead(which I really do not advise), then you're going to have to sit and wait for some to come in stock because I can't find any under $700, and they're absolutely not worth more than $700. The 1080s I'd suggest if you must go with those instead;
[ Register or Signin to view external links. ]
Fairly well priced for a 1080, but none in stock.