Nvidia 1070's should be around 450 Sol/s in Zcash without overclocking or messing with memory, you can make it go up to 480-485 Sol/s by increasing a bit the core clock and the memory. I think mining Zcash now is more profitable than Ethereum at the exact moment I am writing this, I personally have switched all my Nvidia cards to Zcash. It should make you about 2.20 USD daily which is a good amount nowadays considering how down is the profitability of the GPU-mining. Even Eth+Sia is a good option to try.
Are you sure about that? I really doubt it that Ethereum is less profitable than ZCash, I've been mining Zcash for a while, it was pretty profitable since start, till 1 week ago. Now, I've lost more than 30-40% of my daily earnings and cannot move to Ethereum mining due to my cards being only 2GB.