i'm wondering if i'm gonna bye a 1060, 1070 or a 1080?
i use my pc for making videos and gaming (not 4k)
i'm yousing a amd fx-6300 but i'm planing on upgrading to amd fx 9590.
The 1060 6GB should be just fine. If you are sticking with 1080p videos and gaming, then the 1060 should be good. If going to 1440p and light 4K, then upgrade tot he 1070. Or you could get the 1080 to future yourself, if you have the funds.
Well if you want to run Cross Fire then go ahead, but If I am not mistaken, you may not get the ability to have the same power as the GTX 1080. Could be wrong though.
I would look at some cross fire benchmarks. Two 8GB cards, does not mean 16GB.