If you can get 1070Ti <$ 380 go for it.
or else go for RTX 2060.
The performance difference is negligible between those two and remember 1070Ti has +2 gigs of slower ram(future proof for greater res monitors), more CUDA cores, overclocks better and the final cherry on top slightly less heat and power consumption compared to 2060.
The drawback of 1070 Ti currently is the availability and pricing.