With that budget, wait till the 1080 comes out. It's due to be released in the UK tomorrow and in the US either now or soon after, its a beast from what information is out there. Like it was said before, don't bother with SLI on your first build.
Threw this together to give you an idea of what to go for, with in mind of going SLI in the future and assuming you don't have an OS already and you do have a monitor.
I'm sure someone else will want to throw in their two pence.
I went for Windows 10 OS, as that'll support 64gb RAM if you want to upgrade your RAM further than 32gb. If you prefer Windows 7, then you'd have to go with the Pro versions to upgrade further than 32gb, but cost roughly the same as Win10.
[PCPartPicker part...