Resistor plugs usually have an "R" in the type number. Or you can measure the resistance from the terminal on the end to the center electrode, it will be close to zero in a non-resistor plug. Same thing for the cap, measure resistance from where the wire goes to where the plug goes. There is also resistor wire. It has a carbon-fiber center instead of copper. It's almost universally used on cars, if you took your wire off of a car.
To be on the safe side use non-resistor parts throughout. The resistor is just to reduce interference to people's radio and TV reception. Though having one resistor part (not more) should not affect your engine performance.