Sorry if I post this int the wrong section but I am trying to buy a Bitcoin Miner but I am not quite sure where to get the miner from. If any of you guys have experienced with these sites that I mentioned below please feel to tell me what you think cause that will help me out alot. I just don't wanna get scammed especially when I am spending a lot on these machines. I know people say that I should buy the miners from www.bitmain.com but they all out of stock. Thank you.

https://coinminingcentral.com/
https://mining.sesterce.com/
https://www.canaan.io/
https://www.alibaba.com/