⭐ Merited by philipma1957 (1)
I want to buy a mining machine. Do you have any recommendations?
Check Canaan units it seems they are selling cheaper right now compared to Bitmain. And also if you are a newbie at least read this sticky thread here "First time/Small miner reference for getting started"
How long does it take a state-of-the-art mining machine to mine a Bitcoin? 
Depending on so many things if you talking about the whole Bitcoin you won't be able to mine 1 BTC with a single miner you need 8PH/s to be able to mine 1 BTC every month.