X99 board, 5820k, 16GB DDR4, EVGA supernova 850W Gold, and you'll have the basis for a machine that is a good balance between value and being future-proof.
The 5820K is a 6 core with HT (so 12 threads)
It can run two GPU's fine (5820K 28 PCI lanes), buying more than two is generally stupid, better off just buying stronger cards by that stage.
The EVGA 850W comes with a 10 year warranty once registered and will power the system and 2 x 980ti's/300 series. Gold rating is a couple of percent lower than platinum with a much lower price tag.
Could even just buy 8GB DDR4 to begin with, saving more cash.
Buy an R9 290 as a card to get you by for 1440p, they are relatively cheap and pretty powerful. You can get them second hand for peanuts.
Edited by Casey Ryback - 5/17/15 at 5:33am