I just bought the Metrolux II timer from Calumet for my Zone VI enlarger. It sells for $324.00 and the cord to the compensating plug in the head is another $20. dollars. Zone VI sells one also for about the same price but the timer is not digital. OTher than that they are about the same.
If you need the sensor that has to be in the head for this to work it is $70.00. Since the head you bought is a Zone VI I don't think you need the sensor.