GTX1060 will range from 250-300 Sol/s.
GTX1070 will range from 430-450 Sol/s.
GTX1070ti/1080 will range from 470-500 Sol/s.
GTX1080ti will range from 700-750 Sol/s.
Now, according to your local prices, calculate the best possible scenario to hit 1200 Sol/s with least amount of price.