Yeah probably, its a question of RAM as well as cores when you go above 1080p. Dual 770s would still only be 4GB though unless you went for 2x4GB cards. I'd personally go for a single 780 (Ti if you can afford it) and then in a year or two when you want to go 4k put another one in. Or, by that time the cards may be better suited to 4k anyway so just pick one of those up.
I would recommend getting the card when you get the 4k. Cards and demands change. SLI 770s (4GB) would be the bare minimum in my opinion, with SLI 780Tis recommended. Perhaps the R9-295x2 is a good option, due to its vram etc.