It's a yes and yes in both questions! Where i live, we've 220v 50hz.
My A1000 (NTSC) and 1080 (NTSC) are both working great.
A step-down transformer is all you need. It's appliances like alarm clocks that don't work properly with the 60hz to 50hz difference. They work alright, but tend to miss the timing..
As about the 1070, yes, as long as it's RGB (which it is), you can plug it to any Amiga you want.
