The 1070 has way better price/perfromance and it can do 1440p and 1080p 144Hz very well.
Though, the 290 being still quite capable in 1080p, i would wait until october for AMD's Vega cards to come out that will compete with the 1080 and 1070.
AMD has FreeSync which works just as well as G-Sync, plus, even if you still decide on Nvidia, prices are bound to come down at some point.
Regardless, atleast wait a couple of weeks for 1070 prices to settle as now they are inflated by high demand.