"Lightning" effect on stage - any tips for equipment?

Hi, Staging a production of Agatha Christie's And then there were none. Am hoping to have the visual effect of flashes of lightning. We hope to syncronise this with an audio track, however this is not necessary. small-medium theatre, 200ppl. Has anyone had any experience, or know of any really good equipment? I am trying to avoid the standard "flash x times a second" type of strobe light. Reply here, or email me at sono_maschile@yahoo.it Thanks, adam