I would not do the step by step upgrade from 970 to 1070. It is going to be a lot more expensive, and there are probably going to be better cards on the market by the time upgrading would be a good idea. If you have the spare cash to get the 1070 then go for it. It is an awesome card with a lot of performance and overclocking potential. If not, I would(again) advice going for the Fury. With better DX12 and Vulcan performance compared to the 970, it will last longer before it becomes outdated. It also helps that AMD got FreeSync monitors, which act in more or less the same way as G-Sync(Ive heard arguments from both sides as to which is better) but FreeSync is a lot cheaper.
Also, I would not personally go for the Hydro. Nothing wrong with the card, but the pump makes the card a lot louder. I also prefer fans because there are less stuff to go wrong, but again, personal preference.