Welcome aboard. A 4 terminal ballast resistor requires a 5 pin ECU but a 2 terminal ballast(what you have) will work w a 5 or a 4 pin ECU. A MP "chrome box" ECU is a very good choice both for reliability and performance but for the money you might grab a parts house one(4 pin if they have em) & get it going. This is a round capacitor connected to the positive primary terminal?. I'd leave it on, helps w voltage surges.