NGK is just a brand. Their equivalent part number will be an identical heat range to the standard Ford/Motorcraft plug.
If the car is standard, stick with stock heat range - if you want to go NGK, then thats fine, theres literally nothing in it in terms of performance to be gained.

People are only going NGK when using stage x engines, because Ford don't offer different heat ranges out of the box. Of course plugs from lets say a Focus RS might fit and be a colder plug, but without someone finding out that level of detail, its easier to just buy a standard off the shelf NGK at a colder temp.