Which timing light should I buy?

I just got off the phone with MAC Tech Service. The timing lights have copper core leads and with the multi spark and the noise the copper core picks up, it drives the advance circuitry crazy. If the leads were shielded it would help but there's still the multiple sparks. The old MAC lights were made by Actron and may have had shielded wires in the lead set. Actron still makes lights and OTC has some good looking ones with metal pickups and detachable leadsets in standard, dial and digital advance. tmm