what hardware to buy?

Hi, expert,

I am looking at what Arduino hardware to buy and there are quite some choices and I am not really a hardware expert and I don't know what I should choose. I am hoping that I could get some help here. Here are my requirements for the hardware:

  1. able to plug into the power outlet (with or without some extension), possibly convert to a power meter later. Or control the power on and off as well
  2. Need to be able to use Wifi to communicate with other computer or even internet.

Please let me know if it is possible with current hardware and which is best choice.

Thanks in advance for your help. Any suggestion is really appreciated.