seems like you have money to burn to me
😀
I personally would wait for the RX 480 for the plain affordability, AMD showed that 2x 480 beats out a single 1080 and for $300 cheaper however that was just in that single test they did (although it should be noted that if the 1080 could actually run the game without being given slight headstarts it would be a more reliable test
😛).
But I encourage you to wait to see the verdict on the scalability of the 480 and if its as good as that of the last generation of R9 300 series cards then seems a no-brainer to go with the dual 480 or more setup
just my 2 cents