Which country you're located? each country has its own
mains voltage rating (aka voltage rating) in the electrical socket. Be sure to look at the "Residential voltage" column in the table, unless you're in some science lab...
There's only 2 choices: 110V (If you're in the US & other countries that use 110V) or 220V
Then go with a 100V cable with 10A or 240V cable with 5A as suggested above, depending on your country's mains voltage rating.
There's nothing wrong with using after market power cords (been using one myself since the power cord that came with my PSU has a EU male end, not what I needed), as long as the
quality is good (aka don't buy cheap power cords that are of poor quality, or you are introducing a failure point/fire hazard).