Seeing the performance of the 1080 is far superior to both the Vega cards, and pricewise it lands right in the middle, I think it is the best choice for me. I have never played with Gsync or Freesync before, so I wouldn't be missing it, to put it one way. Also, the card you recommended has a promo right now where it comes with a $20 Steam card, so that's pretty nice.
Yea, It is hard to justify the cost of AMD cards when nvidia cards are coming down in price now. I wasn't trying to convert you to nvidia as you stated you wanted AMD, but sometimes it just makes more sense. look at it this way, the vega 64 is roughly on par with the 1080 (slightly slower is most cases) BUT with freesync, those performance drops won't be noticed on the screen and with freesync it gives you the ability to push your card to the same visual quality as the 1080 (maybe even slightly higher) while maintaining smoothness. In terms or raw power and a better price point, yes the 1080 wins. However, if you go g-sync in the future, everything i just said goes out the window and nvidia wins lol.
That's not a bad deal if you need a psu. and a decent 1080, I personally just prefer MSI's cooling solutions better. but, I run my 1080 on a corsair cx 500 watt and have both cpu and gpu overclocked without and power issues, just fyi.