to my knowledge currently the most optimized card you can get for theory of mining is actually the 1060, though I don't have a direct source to quote on this subject, it's been said that with unofficial drivers and the correct software you can optimize the highest hashrate to lowest power usage ratio not to mention the price point on the 1060 is somewhat lower.
look into your options on the 1060 and see if you can find something that satisfies both of your needs, that's the best suggestion I can give you as an economic gamer who also mines.
I actually have a zotac 1060 but the memory is hynix,
and i overclock from 15mh to 19mh.
but it took around 90watt
I was thinking that since the difficulty is going to keep increase, in long term i think I should buy gtx 1070 that generate around 25mh.
