The Zotac twin fan will be similar to a stock 2060 in performance. In the review below the AMP was 3% better fps than the stock 2060. The AMP has a factory overclock, which you can overclock the twin fan when you get home. I would go with whichever is the cheapest as both have good cooling and the chips inside are the same Nvidia chips.
Isn't overclocking bad for your gc? If so, does it mean the amp version have lower lifespan?
The GPU will long be obsolete before it dies from a factory overclock. Dont worry about that.
All the chips inside are made by Nvidia. The only difference is cooling and binning (factory overclocks). The cooling for both of those cards are the same. The higher clocked GPU (AMP) has been binned by Zotac and they put a factory overclock on it. It wont hurt the GPU. You can overclock the chip yourself at home. You may be able to reach the factory OC on the twin fan model, or not. The AMP model just guarantees that you will.
Get the cheaper of the cards. Galax is fine too. Remember, the chips inside are all made by Nvidia.