If they are offering a "3gb or 6gb 1060" and you got a 3gb or 6gb 1060 when you picked one, then you got what you paid for. If it didn't list dual fan or single fan, there's nothing sketchy going on.
One thing, as a general rule, ALL cards of a type perform the same. The same as in if you ran games on them side by side, you wouldn't be able to tell which is which. There might be fps differences showing up in benchmarks but in real world use it doesn't matter.
The 3gb 1060 is not as fast as the 6gb 1060, that's where the larger performance difference is. But you chose the 6gb so you have the fastest 1060. The other stuff, how many fans, how large or small the card is, that's really more personal preference than anything else.
Finally, a lot of sellers buy in bulk and that's how they keep costs down so their prices are lower. They may buy from different suppliers, depending on who is offering the best price at the time. This might be why they don't specify which 1060 they offer since they may get different ones each time they buy some.
edit: There's no difference from a practical sense between those CPUs in gaming at 1080p 60hz. The videocard caps performance. This is in newer games. Also, the 7700K is for overclocking and that's where you'd get your value. Meaning if overclocking isn't your thing then buying that CPU is a waste.