Just remember the gtx 970 has 3.5 gb faster vram and 0.5 very slow vram. It is effectively a 3.5 gb vram card. If you are looking for future proofing I'd wait for the AMD 300 series. Also remember the ROPS, Cache and Bandwidth is lower than advertised.
There's no such thing as "future proofing". Waiting for AMD's cards isn't going to change anything, really. All you're doing is delaying the inevitable and nothing more.